Eli5: Why did a day feel forever at age 10, but now at 25 it feels like 2 hours?



Eli5: Why did a day feel forever at age 10, but now at 25 it feels like 2 hours?

In: Biology

I’ve always heard that the faster your heartbeat, the slower time feels. So the 70 year lifetime of an elephant feels just like the 28 day lifetime of a fly. So when your younger it’s long since your heart beats fast. As you get older it speeds up because your heartbeat slows down.

In short : We have no clue exactly why it feels like that

The predominant theory : That day took up a higher percentage of your life at 10 than at 25. One day at 10 is roughly 1/3650th of your life, whereas at 25 one day is roughly 1/9125th of your life. Another factor that plays into it is that at 10 you’re still gaining a lot of knowledge every day, your brain has to record more stuff that may or may not be important later on, but at 25 your life is probably more mundane, you’re falling into a much more consistent routine and your learning isn’t as broad as before.

Our sense of time is relative. 1 day at 5 y.o. is ~0.05% of your life, but at 10 it is ~0.027% and at 25 it is 0.01%. A day is less and less time. I always hear the analogy of a drop of water. It is significant in a spoonful of water, noticeable in a bucket of water, inconsequential in a pool of water and unnoticeable in an ocean of water.

Memory and the feeling of time passing are both proven to be zipfian in nature (logarithmic decay i think?)

https://youtu.be/fCn8zs912OE here’s a Vsauce video that talks about it

I think there are two parts that definitely contribute to this:

1. When you’re young, you’ve lived fewer days of your life than now. One day to a five year old is a greater chunk of that person’s life than a fifty year old, who’s lived several times as many days as the five year old. In addition, when you’re young, you’ve seen less of what life and the world has to offer, so you’re bound to learn new things more often. This leads to part two…

2. Finding new experiences can make you slow down and think about life sometimes, and with each day usually comes the same routines, habits, and expected things. This can feel even faster if you manage to have the same job at the same employer at the same location for most of your life. It’s like how your nose gets used to the smell of your house and starts to ignore it. Eventually you might live your average day on autopilot.

On average, adults are far busier than children. Time tends to feel like it passes faster the busier you are. Imagine a day in the life of a 10 year old vs that of a 25 year old. The 10 year old has school and some homework. The 25 year old has work, maybe social obligations, perhaps a lover, a family to take care of, Bill’s to sort through, health appts to make, taxes to pay, politicians to vote for, sex to have, online forums to argue in, and on and on.

One of E.E.”Doc” Smith’s characters may have put it best:

_Subjective time is proportional to the amount of learning events experienced._

–Dave, I’m 56. You ain’t seen nuttin’ yet.