Why Life Speeds Up As You Get Older? transcript

When you were 7 years old, summer lasted forever. You remember that. Not the details, not what you ate or what shoes you wore, but that feeling. June stretched out ahead of you like an ocean. Every single day had weight to it. You could live an entire life between breakfast and dinner. You remember lying in the grass watching clouds for what felt like hours, and it still wasn't enough to fill the day. Now you're an adult, and somehow yesterday was March, and right now it's already June.

You blinked and an entire season vanished. Whole months dissolve before you even register they've started. Everybody keeps saying this, "Where did the time go?" The time didn't go anywhere. Your brain did. The most common explanation people give for this is mathematical. It's called the proportional theory. When you're 5 years old, 1 year is 20% of your entire existence. That's massive. A single summer at that age makes up a significant chunk of everything you've ever experienced.

But when you're 50, 1 year is just 2% of your life. So, each year should feel proportionally smaller compared to the growing total behind it. And there's some truth to that. Intuitively, it makes sense. A year does mean more when you haven't lived many of them. But the theory starts to collapse when you push on it even slightly. If you actually plot this out, 1 year as a percentage of your life at every age, and add up the total perceived time underneath that curve, you'll find that by age 6, half of your entire subjective life is already gone, before you can even read.

No 6-year-old on Earth walks around feeling like the best part is behind them. The proportional theory treats your brain like a calculator running simple division. But your brain doesn't do math with time. It does something far more complicated. Your brain has an internal clock. It's an actual timing mechanism built from the firing rate of your neurons, the speed at which electrical signals travel through your nervous system, and neuroscientists have been measuring this speed for decades.

And what they found is consistent. The firing of your neurons peaks in childhood. Then it begins to decline year after year for the rest of your life. When you were young, your neurons fired rapidly, which meant your brain was capturing more snapshots of the world per second. More data points packed into every passing moment. Your brain was essentially over sampling reality. And because it was processing more information per second, each second felt fuller, heavier, longer.

As you age, the clock slows down. Your neurons fire less frequently. The same external hour passes, but your brain captures fewer moments within it. The world hasn't sped up. Your sampling rate has dropped. In 2019, Adrian Bejan, a professor of mechanical engineering at Duke University, published a paper that put hard physics behind this. He measured how the speed of neural signal transmission changes over a lifetime and found something straightforward.

As we age, the pathways those signals travel through become longer and more complex. Each impulse takes slightly more time to reach its destination. Which means in any given second, an older brain processes fewer mental images than a younger one. The world outside keeps moving at the same pace it always has, but the brain is sampling less and less of it with every passing year. You didn't lose the time. Your brain just stopped capturing all of it.

But the slowing clock is only half the equation. Because there's a second mechanism layered on top of it, and this one doesn't just change how fast time feels in the moment. It changes how much of your life you actually remember afterward. When you were a child, nearly everything you encountered was brand new. The first time you saw the ocean, the first time you tasted something you couldn't name, the first time you slept at someone else's house and the ceiling looked wrong in the dark.

Every single day delivered experiences your brain had never processed before. And when your brain encounters something genuinely unfamiliar, it doesn't coast. It lights up. It fires across multiple regions of the cortex at once. It builds fresh neural connections. It encodes detailed, high-resolution memories of what just happened. All of that takes enormous energy. At age five, your brain consumes roughly 66% of your body's total resting calories. 2/3 of every single thing you eat, burned by a 3-lb organ trying to make sense of a world it has never seen before.

And here's why that matters. Your brain has a second way of estimating how long something lasted, completely separate from the neural clock. It counts memories. It looks at how much information it stored during an experience. And the more detail it encoded, the more memories it formed. Your neural clock governs how time feels while you're living it. Your memory density governs how long it feels when you remember it. And as you get older, both of them start working against you at the same time.

Researchers have tested the memory side of this directly. When people are shown a sequence of identical images followed by a single, new, unexpected image, they consistently report that the new image stayed on screen longer than the others. It didn't. Every image was displayed for exactly the same duration. But their brains invested more processing power in the unfamiliar one, encoded it more deeply, and that extra encoding created the subjective feeling of stretched time.

Fear produces the same effect, just at a much larger scale. Studies of skydivers and people involved in car accidents consistently show that they judge terrifying experiences as lasting far longer than they actually did. Their brains, flooded with adrenaline, suddenly start recording at maximum resolution. Every fraction of a second gets captured in vivid detail. And when they replay the memory afterward, all that extra data makes the experience feel like it unfolded in slow motion.

Not because time actually slowed, because the brain wrote down everything. This is why childhood felt so vast. Your neural clock was running quickly, so every moment felt long while you were living it. And your brain was drowning in novelty, encoding everything in rich detail. So, every day felt enormous when you looked back on it. Both systems were working in your favor. Time felt slow in the moment and long in memory.

That's why a single summer at age eight can feel like it lasted longer than your entire 27th year. Now, look at your life today. You drive the same route. You eat at the same places. You talk to the same people about the same things. Your neural clock has slowed, so each moment already feels thinner than it used to. And on top of that, your brain recognizes nearly everything around it. So, it doesn't bother recording it in detail.

It shortcuts. It compresses. It files an entire week under one label. Monday through Friday becomes a smear. A month becomes nothing really happened. A year becomes I don't know where that went. The year went exactly where it always goes. Your brain just stopped writing it down. And here's where it turns into something you can't ignore. Because buried inside these two mechanisms is a paradox that governs your entire experience of being alive.

Think about your last good vacation. If it was truly good, it probably flew by. The days vanished. You kept saying, "I can't believe we leave tomorrow." In the moment, time felt impossibly fast because you were engaged, absorbed, fully present. Your brain wasn't watching the clock. But now, months later, that trip probably feels like it lasted a long time in your memory because every day was different. Your brain formed dense, vivid memories from all that novelty.

And it reads all that stored data as evidence of duration. Now, think about a boring Tuesday at work. Nothing happens. The clock barely moves. Every minute drags. But a week later, that Tuesday is gone. Your brain stored almost nothing about it. In retrospect, it barely exists. The moments that feel longest while you're living them leave the shortest memories. And the moments that vanish fastest in real time leave the longest impressions behind.

Which means there is a trade-off built into the way you you time. And no one warns you about it. A life of routine and comfort feels manageable day by day, but disappears in memory. A life of novelty and challenge flies by in the moment, but stretches out enormously when you look back. You cannot have both. You have to choose which version of your life you want to be long, and that choice is happening right now. Because you are going to wake up tomorrow and do the same thing you did today.

Same alarm, same coffee, same commute. Your brain, running on its slower clock and starving for novelty you're no longer giving it, is going to compress the entire day into almost nothing. Next month, you'll wonder where it went. Next year, you'll wonder where your 30s went. And eventually, you'll look back at decades of your life, and they'll feel like they lasted a few weeks. Not because time sped up, because your days became invisible.

Your childhood felt like a lifetime because every day was the first time your brain had seen the world. Your adulthood feels like a time lapse because every day is a rerun. Your brain has already decided that this isn't worth recording. The clock on the wall hasn't changed speed, not even once. But the one inside your head has been slowing down since the day you were born. And the world around you stopped surprising your brain a long time ago.

Those two facts together are the reason your life feels like it's accelerating. And the only thing that slows it down is something your brain has been asking you for since you stopped being a child. And what I suggest you do is to go see new places every day.