I think a lot of it has to do with the quite heavy expectations that historically came with age and the demand to conform in a certain way. For example you see

I think a lot of it has to do with the quite heavy expectations that historically came with age and the demand to conform in a certain way. For example you see a lot of people today who grew up on the internet and are now into their 40s say "I'm too old for this, I shouldn't enjoy this as much" etc. The expectation to behave a certain way and what people really want creates a sort of mismatch. And really it's kind of silly because when someone is 50 and says they feel like they're 35 that's probably because there's really not that much of a difference. Their brain just works all the same. The reverse is true as well I think. A lot of kids 'feel older' in their head than they are and that's probably just because they're not as different as we treat them. That we treat older and younger people like different species sometimes has always been weird to me.