You know that time is going by just because the others remind you that's your birthday, but, apart from that, everything seems to be and remain the same.
Until you work with a new colleague, 10 years younger than you.
You look at her and you can tell that her skin is fresh,
You see the way she works and you can tell that she has no experience.
She asks you what to do, how to do, what is better, what is worse, and you have no problem in helping her, You know the answers because you are older. That's why.
You feel wise and you are.
She is scared of almost everything and you are not.
Even in a completely new situation, you would know how to move, what would be the next, right step. You have seen/done/lived enough.
Above all she has that idea of the future that you do not have anymore and you do not remember when you stopped having it.
She does not say it, but you can tell that she behaves as if she had millions of choices ahead.
The good part of getting old is that you have much more fun living, you're not scared, you enjoy life more. Which is not unimportant, at all.
(she thinks that at 33 people are old, 33 for her is too far. She does not know that one of the best aspects of getting old is that you really start having good sex)