Authors:

A man doesn't grow old because he has lived a certain number of years. A man grows old when he deserts his ideal. The years may wrinkle his skin, but deserting his ideal wrinkles his soul.

Brennan Manning (2008). “The Ragamuffin Gospel: Good News for the Bedraggled, Beat-Up, and Burnt Out”, p.120, Multnomah
A man doesn't grow old because he has lived a certain number of years. A man grows old when he deserts his ideal. The years may wrinkle his skin, but deserting his ideal wrinkles his soul.