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 always figured it was how much more you squeeze into your day as you get older. Also, the stuff you cram in is monotonous.

I figured after retirement your time flies because of age and requirement to rest more.