To me, old age is always fifteen years older than I am.

Old age is always 15 years older than I am.

Forty is the old age of youth; fifty is the youth of old age.

This wine is forty years old. It certainly doesn't show its age. Latin: Hoc vinum Falernum annorum quadragenta est. Bene aetatem fert.

What most persons consider as virtue, after the age of 40 is simply a loss of energy

At 20 years of age the will reigns; at 30 the wit; at 40 the judgement.