This old tale:
You have three aspects of life and can only enjoy two at once - time, money, energy.
When you're young, you have time and energy but no money.
In the middle, you have money and energy but no time.
Towards the end you have time, money, but no energy to really enjoy it.
I still make very infrequent trips to the go-go's and enjoy stroking a beautiful young thing or two, but the get-up-and-go has gone-up-and-got. Still no regrets.