Women in their 40s have the best sex of them all?

A story on The Guardian by Joanna Moorhead claims that surveys show that women in their 40s are having the best sex of their lives.

But is this down to self-esteem, hormones - or affairs?

Obvously it is because women our age know what we want. Unfortunately I ahve many friends that are getting none cause they are either with the wrong man or with no man at all.