“Nobody grows old merely by living a number of years. We grow old by deserting our ideals. Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul
“My health may be better preserved if I exert myself less, but in the end doesn't each person give his life for his calling?
“Medicine is my lawful wife and literature my mistress; when I get tired of one, I spend the night with the other.
“While one finds company in himself and his pursuits, he cannot feel old, no matter what his years may be