Youth is wonderful. It's a shame to waste it on the young.

I was young and foolish then; now I am old and foolish

It's a good idea to obey all the rules when you're young just so you'll have the strength to break them when you're old

The heart is the real Fountain of Youth.

Genius has no youth, but starts with the ripeness of age and old experience.

Life would be infinitely happier if we could only be born at the age of eighty and gradually approach eighteen