But do we really experience time moving faster as we age? Probably not. BBC science writer Claudia Hammond’s recent article suggests that the idea that time accelerates as we age is mostly a myth. We measure time’s objective passing about the same at any age. But, as she says in her book, Time Warped: Unlocking the mysteries of Time Perception, the experience of time’s passing “depends on the time frame you are considering. In time perception studies, adults in a mid-life report that the hours and days pass at what feels like a normal speed; it is the years that flash by.”

Hammond believes this is because we assess time in two different ways. We can look at how fast time seems to pass in the present, or we can look retrospectively at how fast previous years or decades seemed to pass.  Looked at retrospectively, time seems to go faster as we age. “The days still feel as though they pass at an average speed, but we’re surprised when markers of time indicated how many months and years have passed or at how quickly birthdays come round yet again.” But why? Hammond hypothesizes:

Part of the reason is that as we get older life inevitably brings fewer fresh experiences, and more routines. Because we use the number of new memories we form to gauge how much time has passed, an average week that doesn’t loom large in the memory gives the illusion that time is shrinking.

To combat this phenomenon Hammond suggests we fill our time with new experiences. On the other hand, “we do have to ask ourselves whether we really want to slow time down. If you look at the circumstances where evidence tells us that time goes slowly, they include having a very high temperature, feeling rejected and experiencing depression.”

Richard A. Friedman, a professor of clinical psychiatry at Weill Cornell Medical College has also found that the idea that objective time is speeding up as you age is illusory. “On the whole, most of us perceive short intervals of time similarly, regardless of age.” However, “when researchers asked the subjects about the 10-year interval, older subjects were far more likely than the younger subjects to report that the last decade had passed quickly.” So “Why … do older people look back at long stretches of their lives and feel it’s a race to the finish?”

Friedman’s answer is similar to Hammond’s. When you are younger “you are forming a fairly steady stream of new memories of events, places and people.” Then as an adult when “you look back at your childhood experiences, they appear to unfold in slow motion probably because the sheer number of them gives you the impression that they must have taken forever to acquire.”

But this is merely an illusion, the way adults understand the past when they look through the telescope of lost time. This, though, is not an illusion: almost all of us faced far steeper learning curves when we were young. Most adults do not explore and learn about the world the way they did when they were young; adult life lacks the constant discovery and endless novelty of childhood.

“Studies have shown that the greater the cognitive demands of a task, the longer its duration is perceived to be,” so perhaps ” learning new things might slow down our internal sense of time.” This may also be part of the solution to the apparent speeding up of time as we age:

if you want time to slow down, become a student again. Learn something that requires sustained effort; do something novel. Put down the thriller when you’re sitting on the beach and break out a book on evolutionary theory or Spanish for beginners or a how-to book on something you’ve always wanted to do. Take a new route to work; vacation at an unknown spot. And take your sweet time about it.

I think this is right. We can squeeze a bit more out of life by continually developing. After all, the art of staying young is in large part a matter of continually learning new truths, and unlearning old falsehoods.