In the 19th century, a French philosopher called Paul Janet proposed that time appears to accelerate by the proportion of life already lived. A year for a ten-year-old is one-tenth of everything they know. The same year for a forty-year-old is one-fortieth. The math is simple. Each year is a smaller fraction of the whole than the one before it.
The proportional theory has held up for over a century because it captures something true in the abstract. It just doesn’t quite capture what we actually feel, which is less a calculation than a texture. Some years feel enormous. Others feel like they came and went without leaving much of a mark. The arithmetic alone doesn’t explain the difference.
The neuroscientist David Eagleman has offered a second account that sits next to Janet’s, and I find it the more relevant of the two. As we age, he writes, “you develop more compressed representations of events, and the memories to be read out are correspondingly impoverished. When you are a child, and everything is novel, the richness of the memory gives the impression of increased time passage.” Novelty makes memories dense. Routine makes them thin. Time is less a clock than a record, and the record thins when the days repeat.
I think about this when I look back at my own life. The year of adult life that feels longest to me in retrospect is my first year in Vietnam. Everything was new — the city, the noise, the food, the language, the person I was becoming. I can still reach inside that year and pull out scenes I haven’t thought about in a decade. The years since have not been less full. They have been less novel, and they have stacked into one another the way similar weeks do. Some of that is the math. Much of it, I suspect, is the memory.
If that’s right, then the speeding-up isn’t really about age. It’s about familiarity. And familiarity has a couple of levers.
The obvious one is novelty: change the city, change the route, change the work. Eagleman’s prescription is roughly that simple — keep introducing things the brain hasn’t seen before. That works, and I’ve felt it work. But it isn’t always available. Much of life is lived in roughly the same rooms.
The less obvious lever, and the one that interests me more, is probably attention. For me focusing properly on a single thing seems to do something similar to novelty. When I sit with one piece of writing for a long stretch and let it actually have me, the afternoon comes back to me later with edges. The hours have shape. The same hours spent skating between tabs and notifications and half-finished thoughts don’t come back at all. They’re gone before they ended.
This is not news to anyone who has lost an evening to a phone. What’s interesting is the inverse — that depth of attention, not just freshness of input, can also produce the dense memories Eagleman is describing. Novelty pulls the brain into a new mode because it can’t predict what’s coming next. Sustained attention does something like the same thing from the other direction: it forces a closer look at material the brain would otherwise smooth over and forget. Either way you get the texture back.
I’m not entirely sure what to do with this beyond the obvious. The years that have felt longest to me, on either reading, have been the ones where I either showed up somewhere completely new or stayed with one thing long enough to notice it. The years that have blurred have been the ones where I did neither — where I was busy without being attentive, and where each week looked enough like the last that the brain didn’t bother filing them separately.
I’d argue that a year of attention does more than a year of distraction. That sounds like a slogan, and probably is one, but it tracks for me in the only way I can really test these things, which is by looking back at what I remember and what I don’t. The clock didn’t move differently. Something else did.
