"It's going to happen to all of us. And it's going to happen to you too!", we could say, almost echoing Grandpa Simpson's words in that episode about aging. And there's no way around it! Even as you read this, your cells are degrading, producing inferior copies of themselves every second. And getting old is quite annoying, to be honest. Because on top of the progressive loss of strength, aching bones, memory loss and mental sluggishness, among other equally dreadful things, we also have to put up with the most absurd joke in the entire universe: as we age, we perceive the passage of time faster.
In other words, we are born with one foot on an accelerator that we press progressively as the years go by, until we finally crash into the great wall of our own end. No brakes! Straight ahead, and faster and faster. If there is a creator, he surely has a strange sense of humor.
And this is nothing new. Every person ever born, who didn't die too young, has experienced it. You can notice it yourself, remembering how a week dragged by when you were small, and how it flies by now that you're a bit older. Can you notice it? Well, that same thing will keep happening to you at a constantly accelerating rate, until the day you die. Yippee!
Perception is relative to the total time lived
The most interesting thing is that there is still no answer as to why it happens. After all, we are dealing with human perception, something really difficult to measure. There are, as always, many beautiful hypotheses as to why things are the way they are. Among those hypotheses, one of the most interesting is that proposed by Paul Janet, a French philosopher born in 1823. To understand Janet's hypothesis in an easy and didactic way, the best thing is to refer you to the interactive infographic created by my namesake Maximilian Kiener, which you can access by clicking on the photo below.
If you don't feel like looking at infographics, here's a summary: it says that the way we perceive time is relative to the total amount of time we've lived. For example, at two years old, a year is half of the total time you've lived. Therefore, an eternity. At fifty, however, a year is a fiftieth of the total time lived. That's why, compared to everything we've already been through, it seems like very little.
According to Janet, the perception of time is not tied to the present, but rather to the past. In other words, it's a constant process of comparison between a concept that never changes (time, hours, years) and an incremental value (our accumulated past). According to this hypothesis, to give more examples, assuming you live to 100, HALF of your "perceived life" ends at age 7. Curse you, time!
David Eagleman's hypothesis
From personal experience, and since they are all hypotheses, I'm inclined to believe more in the hypothesis proposed by neuroscientist David Eagleman, which links the perception of time to the effort our brain makes to understand new things. As kids, as we learn all we need to know about this world, we are processing new information at every moment, so the brain has to be super active and perceives the passage of time in a more active way as well.
As we age, the world begins to look more and more familiar and routine, we stop studying and learning, all experiences fit into things we already know, so our brain doesn't make any effort and goes into an automatic mode in which it barely perceives the passing of time, because everything is the same as before.
Similarly, the number of memorable experiences that serve as milestones in our timeline, very useful for orienting ourselves in something we can't control, decreases as we grow older. Between the first bike, the first kiss, the first time we went to school, etc., there's very little time difference. However, aging ungracefully, one sooner or later finds oneself looking back and remembering that that highly memorable thing that happened once was like 10 years ago! Of course, it seems like yesterday because all the time in between has been exactly the same and you can't find a way to locate yourself in so much homogeneity.
In short, if we believe Eagleman, to live more years, or at least to perceive that we live more years (which is more or less the same), we not only have to force ourselves to learn new things all the time and be willing to embrace all possible changes, but also lead a life where memorable events don't have too much distance between them. In other words, a life of learning, adventures and unprecedented experiences. Not bad at all, eh.
