Sometimes people ask me why time seems to move faster as we age.

Recently the question has morphed into something closer to: Is there any way to harness this effect to make certain periods of time move more quickly? As in, for example, the next four years or so. How embroiled in the news should I be? Should I count days? Should I wear a watch?

I’m not a theoretical physicist, and I rarely claim to be. People tend to imagine I know everything about everything involving the nervous system because I went to medical school. So maybe that makes sense in that the “time” we usually talk about is a matter of perception. We conceptualize time through metaphors that project it along a straight line—before and after, long and short, earlier and later—as a function of how our perceptions relate to other perceptions. In the same way, the accuracy of any given clock is only relative to other clocks.

Because time doesn’t clearly exist outside of our own experience of it, there are ways to manipulate that experience. Take peyote, as an example. As one user put it, “Peyote makes time slow down, and at a certain point your whole perception of time vanishes, just because it is not important anymore.” There’s also sensory deprivation. We lose track of time when we’re removed from day-night signals from the sun. The French geologist Michele Siffre popularized this notion in 1962, when he ventured into a cave to study it for two weeks—and then decided to live for a while to examine what he called “the idea of my life.” Deprived of sunlight and clocks, it was an experiment in isolation.

Siffre spent his time writing and reading Plato, sleeping and waking as his body indicated he should. He thought he was doing a reasonable job keeping track of time. At the end of 35 days—by his count—he emerged to find that in fact it had been 60.

I can’t generally advise spending years on peyote or full-time isolation in a cave. The most practical examples of manipulating time perception come from the common observation that the more we think about time, the slower it goes. In his treatise The Principles of Psychology, William James wrote, “A day full of excitement, with no pause, is said to pass ’ere we know it.’ On the contrary, a day full of waiting, of unsatisfied desire for change, will seem a small eternity.”

This is the watched pot that won’t boil. As soon as you go down to the basement and start playing with your model trains, though, there comes the sound of water spilling over onto the stovetop.

That’s the answer that time enthusiast Alan Burdick gave me, too. He’s a staff writer at the The New Yorker, where he covers science. But his personal obsession has long been time––trying to understand it, to exist in ways outside of it, and then, eventually, to embrace it. He now wears a watch. All of this he recounts in his new book, Why Time Flies, and in this week’s episode of If Our Bodies Could Talk:

So the answer, it seems, is to follow whatever activities really get you lost. I think that means something purposeful and not mundane. Though it may also be mundane. Getting into that sort of state—flow, what the psychologist Mihaly Csikszentmihalyi calls “the secret to happiness”—where you’re totally lost in the moment. When you’re spending more time there, it tends to mean you’re less stressed and more productive, and more likely to be doing something purposeful. Something that makes you feel you’re having an impact on other human lives, ideally in a positive way.

Then, before you know it, life has flown by.