Eli5: Why, if at all, does it seem like the years go quicker as you get older?

Question

I hear a lot of people making that remark, that the years go by quicker as you get older.
For me, at least, it seems like that’s only the case if nothing much changes in my life in that year.
To me, years seem to feel like they go slower if there’s lots of new/different things happening.

In: 348

Answer 1

I’ve always rationalised it as; when you’re 10, 5 years is half of your life, when you’re 50, 5 years is a tenth of your life.
The older you get, time seems more insignificant as you’ve experienced it more.