Why the population is aging

 A recent article in the Times [1], shows that many countries are trying to decrease the average age in their country since demographic trends show that the average age is going up. This, of course, puts a strain on the workforce as what is called the old-age dependency ratio [2] is increasing as the ratio of working-age people to pensioners increases.

Several countries have tried solving the problem through 2 methods:

1. Increasing immigration.

2. Incentives for births.

These produce an influx of working-age people.

In general, the demographic ratios are dictated by the link between the birth rate and the death rate [3].

What that article fails to examine is the long term effect of the low birth rate: namely, decreasing the death rate. In fact, the true cause of changing population demographics is the rate of change in the birth rate. Should the birth rate suddenly drop, the death rate will also begin to increase, as fewer new babies result in more deaths per capita as people reach an age of mortality.

However, instantaneously, greater life expectancy and better health provisions can artificially decrease the death rate, resulting in a birth rate that is smaller than the death rate, and increasing average age. But of course, what goes up must come down, and once improvements in life expectancy slow down, the death rate will increase.

[1] https://www.thetimes.co.uk/edition/world/europe-turns-to-benefits-and-migration-to-boost-birth-rates-ml850zmp2

[2] https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/migrationwithintheuk/articles/thechangingukpopulation/2015-01-15

[3] https://pdfs.semanticscholar.org/1260/91f6e25fb3429fd48bf1a8d85fcbc87526f4.pdf

Simulation

I simulated the population and changed the birth rate to twice what it was after 50 years. I then switched it back after 100 years, and we see that the population is only tied to the birth rate, without much dependence on the average life expectancy.

Average life expectancy increasing doesn't affect much since obviously pension age would increase too, proportional to the average life expectancy! So the same percentage of people in the workforce results.

Note that if we assume that it is not just people living longer, but also the chronological age of people being stretched out, then improved health is a good argument for increasing the pension age.

Average life expectancy increases the rate of population growth, but the average age is almost entirely determined by the birth rate per capita.

The simulation also successfully predicts the average age of the world population to a reasonable degree. This may be due to the average life expectancy.

Code

Please visit this webpage to find the code for this simulation.

Being Too Quick to Judge: A Necessary Evil?

Relatively recently, I wrote a review on Goodreads of the book "The Secret Commonwealth" by Philip Pullman. I initially knocked the book a star. I thought it was a 4-star read. I had recently got into the habit of improving my snap judgments on things, under the impression that perhaps my life had been going slower than it should have thus far because of my self-perceived tendency to be indecisive. I had written reviews for Felix, the student newspaper of Imperial College London in the past, and one thing I learned was that it was almost the case that articles that were written quickly tended to be better received by the editors. After all, what was the point in attempting to condense complex ideas into something that people were reading for entertainment; or at least - if I did want to introduce those ideas, I should spread them over the length of the piece, diluting them like a very weak cup of squash, so that people's reading speed would match that of their comprehension, as would my writing speed match that of my own thinking and idea development.

However, I have realised that fast and decisive isn't always best. This realisation came when, a few weeks after reading the book, I realised that I had been mulling over a few of the ideas and characters introduced, with these things affecting my own life and thinking. I thought more deeply about some of the things that had been written and realised that I had overlooked many seemingly minor points, which were gateways to a deeper understanding of the ideas discussed in the story. I am willing to accept that this was perhaps me imposing my own interpretations on a piece of text, but I am more willing to give Philip Pullman the benefit of the doubt and accept that at least some of the things I thought about were intended.

Thus, I went back to my review and revised it from 4 stars to 5 stars. In hindsight, I realised that I had mostly not awarded the book 5 stars because it did not provide perfect gratification instantly upon finishing it. You could argue that this is the reason we have reviews in the first place: different individuals have different opinions, and literature - like any art - is open to interpretation and a far from static subject.

This idea of individuals having opinions is all well and good, but it can also take on a darker side when it materialises in the debate on freedom of speech. If you had to sum up the war going on between what tend to be older generations and younger ones, it would be described as the question of the extent of freedom of speech. Perhaps a better way to express this is - what is the meaning of freedom? One side of the debate believes that freedom of speech means that we should all be entitled to be able to say what we want, free of consequences, or some degree of that thought. The other side believes that the freedom means freedom of an individual to live a life free from hatred and judgement by others, thus speech has moulded into the more general idea of "expression", and by speaking about others we may be limiting those individuals' rights to express themselves. This idea presents itself in all the recent hot topics in the media: Brexit, mask wearing, and Zionism to name but a few. 

So who is right? Is being too quick to judge a poor trait, or one that is necessary in this world where we don't always have time to look into things too deeply? Is it the duty of an individual to spend time considering a subject to its fullest extent before opening their mouth, e.g. to express their views on another person or group?

It is clear that in certain situations, the human instinct to judge quickly is valuable and sometimes even necessary to our survival. If we see a lion in South Africa, we don't stop to consider whether this is a real danger - we make a decision and quickly. It's built into our systems, fight or flight being one form of this.

But it is also clear that there are times when our instinct to judge can harm others. If we see a beggar in the street, do we assume that they are taking drugs, lazy, or drunks just because of the way they look? The reality is that they might be, but they might also not be. But is it right for us to ignore the latter possibility? If that were the case, thousands of unfortunate people living on the streets today would not be receiving vital money, which - in some cases - might be the difference between a life of misery and one that is meaningful.

It is clear that there is no simple answer. Even when we do weigh up the possibility that our assumptions may be wrong, studies of human behaviour as detailed in the book "Thinking Fast and Slow" have demonstrated that our perceptions of probability are very often misguided.

In my opinion, the answer is that we should seek to improve ourselves and listen to others. If they tell us that we are judging too harshly, this is often a signal to sit back, take a moment, and reflect on whether our lines of thinking are based on solid evidence, or if they have been swayed through overexposure to one particular point of view, namely our own. But at the end of the day, we should not do ourselves down for being too quick to judge. Everyone makes mistakes. Indeed, the one person we should never be too quick to judge is very close to home - we should never be too judgemental of ourselves.

Learning out of curiosity: Bubbles of ignorance

The only way to learn is to learn out of curiosity, otherwise, there's no motivation. If you learn due to an external drive, you're not really learning. If you don't have curiosity for something, then learn something else until you find the right questions.

That last point is important - we learn new things because we find out that there are things that don't make sense to us, so we search out answers. If we are simply stamp collecting, then we will have no incentive to learn.

Ernest Rutherford famously said that "All science is either physics or stamp collecting". This demonstrates that had Rutherford tried his hand at biology, he would have epically failed. That's not to say that Rutherford wasn't intelligent, or capable. Indeed, he was probably more intelligent and capable than most people. Rather, he was uninterested. His experiences in the world had led him to the view that nothing other than physics was interesting. He would have seen no point in learning about biology, because it wouldn't have sated his curiosity.

I notice that the times I learn most are when I'm most interested and engaged, and that happens when what I'm learning about seems to answer, or at least hint at answering, questions that I had before. That feeling of discovery when you come across a potential solution to a problem you've had for a long time is a great one.

I suppose the fundamental problem of researchers, is that some problems are simply too big to have straightforward answers. The way to approach them is to use them as motivators, and search for leads. We become a little like detectives trying to solve a mystery. We use our prior experience and our imagination to attempt to find plausible clues, or leads. We will be interested in these leads because they seem like viable ways to answer our burning questions.

Ask any scientist or researcher what they are interested in, and they'll give you a list of topics. I suppose common ones include 'understanding intelligence/consciousness', 'understanding physics', 'curing cancer'. Maybe people are motivated for different reasons, and I'm sure that there are people out there who have an interest in these things because it might bring them riches, fame, or glory. But I feel like it's not really possible to make real progress in a field unless you're motivated by your own curiosity. There were questions we had as children, and they're probably questions that human beings have been trying to answer for thousands of years.

Maybe, ultimately, the question we are all asking is - "Who are we? What does this all mean?". It's a question every child probably asks themselves with or without knowing it, and its motivated humans to build civilisations, and led to the growth of philosophies, religions and other ideologies. All our questions are derivatives of those questions. We need to keep deriving questions until they are within our reach, and attack those, so that we can further penetrate the sea of ignorance in which our little bubbles of knowledge float. Maybe it's a higher-dimensional Non-Euclidean space of ignorance, in fact it almost certainly is. But let's keep penetrating till we hit other bubbles, or (gasp) finally break the surface and smell fresh air.

Can Money Buy Happiness?

A Sisyphean perspective sheds light on the age-old question of whether money can buy happiness.

Photo by Aziz Acharki on Unsplash

During this unusual time, many people, including myself, may be starting to take a more introspective look at themselves and their lives, thinking about their choices and about bigger questions that might otherwise be neglected when we are preoccupied with ordinary life, whatever that is for us. One question that has been on the back burner of my mind for a while is that which forms the title of this piece. It’s a question that has plagued people perhaps ever since money was created. Maybe, even before that, ever since the possession of material goods began to have meaning. It asks whether having more material wealth, more things, or more capacity to obtain (buy) those things, can lead us to states of greater contentment, satisfaction, enjoyment, or whatever else we define happiness to mean.

Well, hidden in that question is an important point — in order for us to ask whether money can buy happiness, it is important to first define what happiness is, as we would with any other commodity. We wouldn’t, for example, walk into a confectionery shop asking for “something sweet”, possibly to a quizzical stare from an understandably confused sales assistant. We would ask instead for a specific type of sweet. Then the sales assistant would heave a sigh of relief and direct us to the appropriate shelf where stacks of said product were neatly lined up, ready for our choosing (and purchase).

Happiness means many different things to different people, at a range of different levels. At an experiential level, we deal in ideas such as “relaxation”, “popularity”, and “lack of stress”. These are all good feelings or experiences, but feelings alone are among the most difficult things to objectively measure. Perhaps we would do better to consider things at the biological level: there are a few chemicals inside our brains that are strongly associated with the broad feeling we call happiness: acetylcholine, dopamine, and serotonin. I won’t attempt to go into the function of each individual chemical here, but each has an important function in different areas of our lives, regulating our motivation to do things, bonding with our peers, and reinforcement of positive behaviour. But those who believe that the human brain is greater than the sum of its parts would vehemently object to us stopping there. Let us instead consider the spiritual or metaphorical level. Many people hold such thoughts as “lack of want”, “feeling at peace with ourselves”, or “contentment”, as goals to strive towards, feeling they will be happy when they achieve these states.

It is clear that there is no single agreed-upon definition of what it means to be happy, so one might argue that it is a difficult to question to answer. The real answer is, that all of this is relative, that there is no wrong answer. What a cop-out, I hear you say, the question is now moot! But this relativity, I would argue, rather than making the question meaningless, actually explains its true essence and enables us to form a general answer that isn’t riddled with conditions and provisos. By agreeing that happiness itself is an experience that is personal to each human being and that one person’s happiness is not necessarily another’s, this can explain the vastly varying definitions of what it means to be happy. We all know what happiness means to us, but we do not necessarily understand what it means for others.

Photo by Sasha Freemind on Unsplash

The study of meaning is a tricky one, namely because it seems absurd for any philosophical study not to assume meaning as an axiom, and if we assume meaning as an axiom in the study of meaning it seems a circular argument. Nevertheless, that hasn’t stopped many great philosophical minds writing books on the subject, one of the most famous being the 20th-century French-Algerian philosopher Albert Camus. In “The Myth of Sisyphus”, Camus references the ancient Greek legend of a man called Sisyphus condemned to spend eternity rolling a rock up a hill, only to have it roll back down again when he reaches the top. Despite the ostensible meaninglessness of this endeavour, Camus concludes that “One must imagine Sisyphus happy”. His reasoning is that Sisyphus’ rock is something that defines his existence — it bootstraps meaning from nothing. Indeed, the moral of his story is that everything we do in life is ultimately meaningless in some sense, and it is only through the relation of the things we do to other things in our lives that they acquire meaning.

Camus’ argument brings me to the key statement — happiness is defined on an individual basis by pursuing or by achieving those things which give our life meaning.

What gives my life meaning will certainly be different from what gives your life meaning. Some ascribe meaning to wealth, some to success, some to becoming the best at what they do in a certain field. Some people derive their meaning from giving to others, from improving others’ lives, from seeing their impact on the world. Some people find their meaning in achieving their ideal self, some from religion, some from their partners, friends, family, and some from their children. The list goes on and is endless and unique to each individual. I’m sure that if you consider your own life, you’ll be able to identify a few key things that give your life a meaning, a purpose, the things that you enjoy doing, or wish you could do. You’ll notice I mentioned wealth. What I will attempt to show is that the pursuit of wealth in itself has no meaning.

Someone recently told me about how he’d seen others in the world become successful at a young age, attributing their success to their upbringing and the circumstances surrounding their birth. I took no issue with this, but I did note that when he talked about success, he talked about it as something desirable, almost conflating it with the idea of happiness. Ironically, it was exactly because these people had acquired so much wealth that this person was citing them as an example of someone who was happier, who was luckier. All too often we are jealous of those people around us, believing that they have better lives than us, wishing that we had what they had. This is perhaps because we see others around us sharing in our desires, complimenting people for being rich or famous. Without this sounding too much like a homily, I truly believe that what many people truly desire is for others to love and respect them, and society has told us that those who are loved and respected are those who are rich, those with power, those with influence. This is perhaps the reason why we ask whether money can buy happiness.

But it is clear that to be loved and respected by those around us we do not have to be rich. Does this mean that those people who strive for riches are mistaken and that money does not buy happiness at all? Well, this is only partly true. Now that we have a working definition of what happiness is — namely, the ability to pursue those things that are meaningful to us, let us take our initial question further. Money is, of course, necessary. A painter living on the streets seems, on the surface, much less likely to be as satisfied in the pursuit of her goal than a painter living in a penthouse apartment overlooking a city skyline. But perhaps we are simply evaluating the quality of others’ lives by the standards we have developed for ourselves. Often we say, and forgive me the trite saying, that the poorest people are the happiest. My belief is that this can be the case because those people that are both poor and simultaneously happy are those who see money for what it truly is — a means to an end, something to facilitate their lives and to help them do things. Money is not something to be stockpiled, so that we can show off how many digits we have at the end of our latest bank statement. People who see the world in this way, who are not necessarily poor, have broken the false link between money and happiness.

As I said, money is essential to our lives. We need money to sustain our livelihoods and to keep us healthy and out of danger, physically and mentally. Money, then, can be seen as giving happiness when it removes barriers in pursuit of those things that give us meaning.

Let’s return to the lives of our two artists, perhaps they are both happy. Perhaps the first artist feels she cannot paint unless she feels secure in the knowledge that she will not have to search for a place to sleep that night. Perhaps part of her meaning in life is having a beautiful skyline view out of her window. If this is her reason for striving to earn money to buy the apartment she has, then money has indeed bought her happiness — it has paved the way for her to achieve what she dreams of. Coming to the second artist, she lives on the streets, but is equally happy. Her dream is to be free to explore the city at night to her heart’s desire, to see those things that others don’t, and to simply have the freedom to paint and draw those things she finds beautiful. She doesn’t particularly care about how others perceive her.

It seems these extreme examples demonstrate that small differences in what people find meaningful can lead to drastic differences in material requirements. On the surface of things, things seem unfair: one artist derives meaning from activities that cost nothing, whereas the other requires expensive rent to pay for her meaning to be fulfilled. However, let us entertain the idea that the first artist simply wanted to see beautiful scenery from her window — she saw meaning in that. In fact, in order to do this, she could equally well have been living in a small apartment at the bottom of an unsightly street. This wouldn’t have prevented her from climbing to the top of the tallest buildings in London each day and looking out on the city. The moral? We derive meaning from our experiences, or what we seek to experience, and there is more than one way to skin a cat.

My conclusion is that money can buy us happiness, in so far as it enables us to do the things we like to do in life. Most things that give our lives meaning are often free, or very inexpensive — pursuing hobbies, spending time with friends and family, and learning new things to quote a few. Problems creep in when we start to conflate money with popularity, status, or likeability. Money alone has no power over us, rather, it is the artificial association of money with these things in our own minds, and the minds of society, that have given the acquisition of riches and material wealth a meaning in itself. To become happy, we need to look inside ourselves and ask what the essential qualities of our dreams are. Perhaps they might cost a bit less than we might have previously thought.

Cairo – More than One Wonder

Houses floating on the Nile (Awammas) – Photo courtesy Hanya El-Geresy (Insta @hanyaelgeresy)

For all Cairo’s wonders, there are none that exceed the magnificence of the pyramids. Those are truly official wonders. But that’s not the Cairo that people see on a day to day basis. There are many more wonders to be found on the streets of the city that never really sleeps.

Cairo, the capital city of Egypt, is an interesting place. It’s a place full of noise, pollution and most of all life. People bustling around dust covered streets dressed in all manner of garb – from the traditional galabiya to the most modern of outfits, it really is a land where old mixes with new. Strolling down the bank of the river Nile at night, you could be forgiven for thinking the water was perfect, sparkling with the reflections of the perpetually-on street lamps and neon lights that blare from shops, restaurants and hotels surrounding the banks. However in reality, it probably wouldn’t be that good an idea to swim in it, let alone drink it.

A swarthy old man in white robes lazes in a broken plastic chair. His eyes flash white with recognition, brilliant against the canvas of a weatherbeaten face. He calls out to us, offering us a ride in his felucca, but we turn him down. He returns to his ordinary position, the same languid expression on his face.

Cairo by day is a different world. The humidity varies from day to day, but you will almost certainly feel in need of a shower if you plan on staying more than a few hours out of the house. The dusty roads are the bane of designer footwear, whose soles and lower parts will have inevitably turned a dusty brown by the time you get back to the hopeful solace of an air-conditioned room. If one is not available, you can always pop into one of the various glass-fronted stores that line the streets; the height of modernity and with air-con to match. Those that look a little more run down will still offer at least a couple of rusty old fans in the corners of the rooms, billowing hot air down onto your head as you gaze longingly into a fridge full of cans of soft drink with familiar names.

Despite its dusty exterior, beneath this Cairo is a city of history. For a second, if you whisk away the dusty film that covers it, treasures will be revealed to you. An ancient archway signalling the spot where an Anglican cathedral once stood. Little black doors where holy men stand, adorning shoes they have taken off to pray, minarets poking their heads over the mishmash of wildly contrasting apartment blocks.

It is of course not only the buildings that make the city. No artwork is really the same without the name behind it. Most modern art could pass for high school work, were it to be viewed in a classroom. But stick a big name on it and you get a proportionally big price. Without the people factor, art is lifeless, and not worth seeing. This statement was never confirmed more strongly than by Cairo’s sprawling landscape of beauty – a post-Imperial, post-apocalyptic biodome where newer buildings have sprouted like trees in between the older, grander structures, that have turned the same colour. Among the windows and terraces, the Egyptians roam. Theirs is a lively people. Egyptians are uniquely resourceful, relaxed and jovial. Get in a taxi cab and ask for a light and the driver will whip out his lighter – that is, if he hasn’t already for his own purposes – gladly offering a few words of chitchat in addition to the flame. Smoking is not just a common occurrence – it is almost expected. No mechanic’s toolbox is complete without the mandatory pack of Marlboro. The people of Cairo will laugh with you however, and be you in need – be in no doubt that help in some form will be along very shortly. That is, if it isn’t there already. Just watch out for the token “it’s nothing” at the end, which is certainly anything but that. Rather, it’s a polite request for you to reward the man who has come selflessly to your aid with a plump 10 Egyptian pounds for his effort.

Egypt is a pot where political turmoil bubbles, however it does so deep under the streets. On the surface, life goes on in its chaotically ordinary way, cars darting in and around each other in a seeming race to get to the end of the road first, their weapon of choice against their competitors being the horn. The horn can take on various different sounds, but like a snowflake, none are the same. There are small squeaks, standard toots and even the deafening blare that would be more suited to a steam train. Then of course, there is the special case of the trucks that have replaced their horns with a small jingle, like the ones that precede tannoy announcements at the airport, but somehow yet more intrusive. Sometimes, a horn isn’t even necessary – the rag and bone man, robabikya, whose voice will be heard throughout the streets at an ungodly hour, is one especially annoying specimen.

Of course, the horn is not always used in a menacing fashion. Like a sword, as well as being used to slay your sworn enemies, it can be used to knight your most loyal friends. Occasionally, you will hear the unmistakable 5-note chant that signals the coming of a wedding procession. Like a reverse thunderstorm, a few moments later, a full symphony orchestra playing the same 5 notes will glide into view, causing great joy to those in the entourage and annoyance of a similar magnitude to those who must grudgingly trace the path behind, possibly on their way home.

No day is complete without fool – a simple bean based stew that is suprisingly filling and delicious. Taste it and you’ll understand why Egyptians eat it on almost a daily basis. It is the national dish of Egypt, alongside another called koshari, which is even more delicious. That one is a dish with a strange history, being based on foods from a variety of cultures – Indian, Italian and British, but it is now completely and unmistakably Egyptian (and don’t even attempt to tell anyone otherwise).

The Undemocratic Rebellion

"Mr Stop Brexit" Steve Bray and a Leave campaigner. Credit: Reuters/Toby Melville.

Reading about Brexit recently I encountered one leave supporter describing the current group of remainers and politicians who are campaigning for remain or a blockade for a no deal Brexit as an ‘undemocratic rebellion’. At first, it might seem obvious – the results of the referendum of 2016 have to be honoured: everyone was given an equal chance and right to vote about whether or not we should stay in the EU.

Well, although it is true that based on the vote we should have left the EU, the fact is that I’m not sure that many people – remainers or leavers - knew at that time what leaving the EU was about, or do now in fact! The government had originally called the referendum as an election tactic to try to sway voters leaning towards less mainstream parties, such as UKIP, back to the conservatives. They never believed that it could ever come to anything. The vote was held in the same patronising way that a parent might tell their 10 year old child that they can live on their own.

The problem is, that if that child actually became serious about leaving the house, the parent would then at least try to question the child’s motives and its means of supporting itself once it has left the house: “How are you going to mortgage that flat in Scotland without a job?”.

The government at the time gone went through with its patronising stance, and afforded the voters the same courtesy: a postcard telling them why we’re better off in the EU. They were arrogantly complacent enough to think that a letter through everyone’s door would suffice to quell the discontent that was bubbling across the country at the time.

Unfortunately, we all know the outcome of this complacency, and you might say that the government got what it deserved. But that is not right – why should the majority (the people) be punished for the actions of the minority (the government that failed to run the country sensibly and treated its voters like children). This includes both leave and remain voters, who were given the opportunity to vote without reasons being given for the vote happening in the first place, apart from the conservative government’s need to maintain its vote-grabbing election promises.

Now we are seeing a turn of the tides in the form of anger amongst the remainers who rightly feel cheated by the outcome. They want their say again on whether Britain should remain in the EU.

These people aren’t “salty” or “remoaners”, they are people who, since the referendum, have come to the realisation that we are leaving a community we have been a part of for over 40 years, that forms a major part of the laws and trade of this country and they are rightly worried about the collective future of the people who inhabit it. The leave campaign was run from a similar standpoint in 2015. There were some questionable motivations, but the need to protect democracy and kick out the people running our country for us from the remote distance of Brussels can be understood. Perhaps this is why the repulsion to anything that smells the slightest bit undemocratic is so hated by those who voted leave.

But we cannot simply carry this result through. We need to realise that the entire fiasco that has been the country since article 50 was triggered has been fuelled not by science, but by opinion. Neither side fully understands the implications of Brexit. The leave campaigners are thrilled, but the truth is that the necessary due diligence has not been carried out – the government has not done what should be its primary job, which is to ensure that the country is safely and fairly run. Now that we are on track to leave the EU by default, people are waking up to that fact and trying to have a proper debate. But it has come too late and it is understandably fuelled by panic.

If the country was a university and Brexit was an exam, people would be furious! The government sprang a test on us at the start of term, then started teaching us the syllabus after everyone had had their grade for the year. Upon finding out that the campaign had been fuelled both by illegal funds and by misinformation about the effects of leaving the EU, people rightly feel cheated. If Brexit were an exam, then it should have been run again to give everyone a fair chance. To be democratic about things, we need an informed debate and then a second referendum.

We need to stop Brexit in its tracks: not permanently, but to carefully consider whether or not we actually want to leave based on real evidence and informed debate, rather than passion. The only way that can happen is by having comprehensive discussions on the subject, framed not as an analysis of what is going to inevitably happen (as government-commissioned reports have been up until now), but as an analysis of whether or not we should be in the EU from the standpoint of a choice being had afterwards. The people deserve the right to have time to think and to make an informed choice. That choice has not been given to them yet and we need it to happen. If such a debate were to happen and it turned out that on balance we would be better off out, then so be it. But we need to have that debate, rather than a decision fuelled by mixed and sporadic analysis funnelled through the media, supporting either leave or remain. We need a balanced and sane discussion about the topic and then a second referendum. We need the government to make up for past errors and do its job. We need to finally be treated as adults who are deciding on their futures, rather than children having fantasies about leaving home.

What is opportunity cost? A matter of life and death.

Opportunity cost is simply the cost of producing a good with reference to what you could have instead produced in the meantime.

You can understand it in terms of the number of hours you have in a day (time is incidentally usually a factor which has to be taken into consideration, along with resources when considering opportunity cost). If you have 12 hours in a day that you can do something useful in, you can do different things. Work, eat, socialise etc.The value of each activity to you as a person may be different, it may even change depending on the number of hours of each thing you do.
If you work for 2 hours you might get 30% of the work you need to do done. Working for another 2 hours might only get you up to 40%, so perhaps you might have better spent those hours resting, or doing something else, so that you can increase the value of the hours you use to work later in the day.
This is a crude explanation of why people take breaks in revision, from an economics perspective.

Another interesting thing to link opportunity cost to, is the production possibilities frontier. Its called a frontier, because it literally is a graphical frontier - a line which divides the areas of the graph where a production point can exist from those that cannot. You can think of the production point as a person on a battlefield. They will have different advantages and disadvantages at different points, perhaps the terrain gets rougher as they go further away from their base. Perhaps they can even cross over into no man's land while still being able to handle the increased difficulty in moving and hiding. It is probably advantageous for them to go further and further away from the base since they will be closer to the enemy and better able to target them. However, if the man decides to stand directly in front of the enemy trench or front line then he is very likely to either get shot cleanly in the face, or simply be taken hostage. The idea is that as the man gets further away from his own base, he is able to aim more accurately (produce more damage), up until a point where he is at the verge of being shot or captured.
Say that there are two enemy bases which he can shoot at, if the man were able to get into a position where he could shoot at just one base, it might not be as efficient, since he would only be able to shoot based on the probability of enemies being in vulnerable positions in one base. If he were as close to the other base as well, while he wasn't shooting at the first base, he could be shooting at the second base, and maximising his DPS (damage per second) - again, doing the same amount of damage in less time is of more intrinsic value (or detriment if you are the enemy). This is gradually become a discussion which sounds more like it is describing a video game than an actual battlefield, but never mind.
So, the man has a problem now. The closer he gets to the other side's base, the further he has to move away from the base he was originally shooting at, because his distraction level is increased by shooting at two bases at the same time. We could in fact draw the two bases on a map and show the limits of the man's reach:

So where is the man's optimum position? Clearly it is the place where he is closest to both bases in terms of distance and where he is ideally safe. We note that if the man travels upwards, he gets closer to the first base, but if he travels right he gets closer to the second base, without affecting his distance from the first base (assuming they are both very long). The man is safest (expends the least amount of effort and produces the least amount of damage) behind his trench in the friendly base.
We note that the red line is the limit of the man's reach. He could be anywhere behind that line. We note that the line is not straight, because the danger and struggle the man faces is not simply linear (it does not increase proportional to) the distance from either base. In fact, it is much more like the force experienced by a negative charge as it approaches an electron, or the force you experience when you press down on a spring, or folding a piece of paper into halves again and again and again. At first it is easy, but as you make progress you get diminishing returns for the same amount of effort you put in (in the case of the electron you would get less distance gained, in the case of the spring, the spring would not get much smaller and in the case of the paper, you would eventually be unable to fold it in half again even though you were trying much harder than you were before).

We can see that because of the diminishing returns the man gets when he tries to approach either of the enemy front-lines, he could substitute some of his gains in one direction for larger gains in the other direction - meaning that he could sacrifice some distance to the orange base for perhaps double the distance to the yellow base. Where is the optimum position? It is where the sum total of the distance to each base is lowest.

The optimum point (assuming that the value of the distance to the bases is proportional to the distance - unlike the danger) is simply the point where the sum of the distances to each base is lowest, or equivalently, the sum of the distances from the man's base in the upwards and rightwards directions is greatest.
If you like maths, you may be thinking that you know exactly how to solve this problem. A common mistake people make is to say that the problem can be solved by finding the point which maximises the radius (or absolute distance from the friendly base). This is incorrect and can be explained by reference to the Pythagorean Theorem, where:

$$x^2 + y^2 = r^2$$

Note that here, if we maximise r, then we are maximising $x^2 + y^2$ rather than $x+y$ (assuming x represents the distance in the rightwards direction and y in the upwards.
Rather we can write:
$z=x+y$
And then we could do partial differentiation with respect to two variables and find the maximum that way.

Linking this back to the production possibilities frontier, the frontier, as you may have guessed - is the line in red and we simply think of the left and bottom sides of the battlefield as axes of a graph (think of someone putting a massive ruler next to them) and also consider the friendly base to be the origin (point (0,0)). Now consider the production point to be the man and you now hopefully understand that the man (or production point) should probably be somewhere in the curved part of the graph. Note that if $x+y$ at the production possibilities frontier was constant then the red line would be a straight line (just equate it to a constant $c$, look: $x+y=c$, $y=-x+c$ i.e. a straight line with a negative gradient and y-intercept c$). You can consider the various values of producing different quantities of two different products (getting closer to any one base), taking into consideration the diminishing returns of production to alter the shape from simply being a straight line. The diminishing returns of production in economics are sometimes explained by the idea that resources being allocated to the production of one product would be more efficient if they were producing a different product. For example, if you focused all of a technology company's resources on producing software, the hardware engineers, who are better at producing hardware, would also work on software, but would produce less value to the company for each hour they worked on the software, compared to if they had been spending those hours working on what they were good, or efficient, at doing.