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David Eagleman was eight when he fell off a roof. A house under construction in the neighbourhood, he stepped onto an edge that gave way, and suddenly there was nothing under his feet. It was a drop of about four metres. The fall lasted, as could be worked out afterwards, roughly 0.86 seconds. In Eagleman’s memory it lasted far longer. Long enough, at any rate, to wonder mid-fall whether this was the same thing Alice felt when she tumbled down the rabbit hole and calmly studied the shelves on the walls on her way down. Falling head-first towards a pile of bricks, he had time for a literary allusion.
The thing wouldn’t let go of him. How could barely a second feel like a small eternity? Had his brain sped up in that moment, seen the world in slow motion, the way Neo dodges bullets in “The Matrix”? Or was memory staging something for him that hadn’t actually happened in the moment itself? Years later, as a neuroscientist in Houston, Eagleman built an experiment to find out exactly that.
He needed real fear, not the toothless laboratory kind. He found it at an amusement park near Dallas, on a structure called SCAD. You’re winched up backwards on a cable, fifteen storeys high, and then the cable releases with a small metallic click. You fall thirty-one metres, about three seconds, before a net catches you below. On a scale of one to ten, every participant afterwards rated the fear a ten.
To each wrist Eagleman strapped a small device he called the perceptual chronometer, essentially a clunky digital watch with numbers flashing on it. Beforehand he had measured for each person individually how fast the numbers could flicker before the eye saw nothing but a blur. During the fall they then flickered just a touch faster than that personal threshold. The idea behind it was elegant. If the brain really shifts into a kind of slow motion in a moment of mortal terror, the numbers should appear slow enough to read. Anyone who can make out the watch in free fall proves that perception genuinely stretched.
Nobody could read them, they stayed a flicker as before. And yet participants estimated their own fall, on average, a good third longer than the falls of the others they had watched. So the sense of stretching was real. It just didn’t arise where Eagleman had first gone looking for it. In free fall, perception ran on as normal. Only afterwards, in memory, did three seconds turn into a felt half-minute.
The reason lies in the way fear writes memories. In danger the amygdala works overtime and makes sure an event is stored especially densely, with more detail, more traces. And here’s the actual trick. When we later estimate how long something took, the brain doesn’t consult an inner clock. It checks how much memory is there. Lots of material means: must have been long. Mortal terror doesn’t stretch time while it’s happening. It just leaves so many traces that the time looks stretched in hindsight.
December Again, Already
Few of us will ever fall backwards off a tower. But the same principle steers an experience almost everyone knows past a certain age, one that feels much more harmless until you look closely: the sense that time is speeding up. That the years are getting shorter. That it’s December again when you barely noticed the summer. As a child a single afternoon dragged on forever, the stretch until the long holidays was a small infinity. At forty, Christmas is over before you’ve finished hanging the baubles.
The oldest explanation for this comes from the French philosopher Paul Janet, who formulated it in 1877. It’s almost too simple to be true, and yet it’s true a fair way. Janet said: every year is measured against the amount of life already behind you. For a five-year-old, a year is a fifth of their entire existence, a huge block. For a fifty-year-old, the same year is a fiftieth, a thin slice. The same twelve months, measured against a yardstick that keeps getting longer, shrink subjectively with each year of life.
As neat as the arithmetic is, it doesn’t explain what we actually experience. Time doesn’t pass at the same speed for all forty-year-olds. Some years feel enormous when you look back on them, the year of a move, a new city, a separation. Others have vanished without leaving a single edge. Pure arithmetic can’t grasp that difference, it treats every year alike. Our experience doesn’t.
Why Routine Swallows Time
Here the same principle comes back into play, the one behind the fall. Eagleman’s second, more convincing explanation runs: we measure past time by the density of memory. As a child, everything is new. Every first taste, every slight on the playground is lived for the first time and stored accordingly richly. The brain lays down whole new structures to fit it all in. In retrospect this time is packed full, and packed full means, to the brain: long.
Over the years much of it turns into repetition. The commute is the same as yesterday, lunch is already familiar, the conversation runs in well-worn grooves. The brain is an efficient organ and sees no reason to store all of that again in full resolution. It lays down a thin trace, a note: same as ever. A week made of nothing but such notes leaves almost nothing for memory to hold on to later. And time that leaves no traces is simply gone in hindsight.
There’s a quirk in this that makes the whole thing properly tricky. A packed, new experience doesn’t actually stretch in the moment, quite the opposite. A trip to an unfamiliar place where you take in new things all day often flies by while you’re living it. Only afterwards, when you think back, does it seem long, because so much fits inside. A sluggish, uneventful week is built the other way round. While it’s running it refuses to pass, every Tuesday afternoon drags. But the moment it’s over it has vanished without a trace, because nothing stuck that it could be pinned to. In the moment, boredom stretches time; in memory it swallows it. With the new, it’s reversed.
Something practical follows from this, and it’s more than the usual advice to travel more often. What stretches time is less the exotic itself than the attention the new demands of you. Something unfamiliar can’t be handled half-asleep, you have to look, your brain can’t predict what comes next. You can give that same looking to the familiar, too. An evening when you’re truly with one thing, a conversation or a piece of work, without hanging off your phone on the side, comes back later with contours, it has a shape. The same hours, half here and half in some feed, are over before they ended. Attention produces the same density as novelty, just from the other direction.
That’s the uncomfortable and at the same time consoling side of it. The speed at which your life passes is not a fixed value that’s settled with age. It depends on how much of what happens you register at all. Eagleman’s three seconds in free fall became half a minute because so much attention was packed into them. Nobody wants to spend their life in mortal terror just to make it feel longer. But what’s left of mortal terror once you take the terror out, the wide-awake, undivided being-there, is available to you every day. It doesn’t lengthen the years on paper. It only sees to it that more of them is left at the end.
An exercise for the coming week
For seven days, take a notebook or your notes app and each evening write down a single sentence: what happened today that I’d still remember in a year? Sometimes it’ll be something big. Most of the time something small you’d otherwise not have noticed, a face on the train, a line from your kid, the light at six. The point isn’t that the day was special. The point is to mark it, to give it an edge that memory can hold on to later.
And then, at some point during the week, do a familiar thing differently. Take the other route to work, or cook something you’ve never cooked. None of it has to be big. It just has to be unusual enough that your brain wakes up and looks more closely.
When you flip back through the week at the end, it’ll probably feel longer than the week before. The time was the same. More of it stayed.
That’s all it takes. The years don’t vanish because they get faster. They vanish because we stop looking at them.
