Guess that´s when you will find out!
Why our sex drive increases as our beauty decreases?
the question is not about the sex drive, but about how GOOD sex is. Experience gives one a measure of confidence, which also has a lot to do with it, I suppose. Women are less apt to just "let it happen", but actually know and are capable to communicate their own desires.
Also, unless we are talking elderly, one isn´t necessarily the most beautiful when very young. I certainly look better now, than I did ten years ago.
Btw - see my hypothesis above...