At thirty man suspects himself a fool; Knows it at forty, and reforms his plan; At fifty chides his infamous delay, Pushes his prudent purpose to resolve; In all the magnanimity of thought Resolves; and re-resolves; then dies the same. And why? Because he thinks himself immortal. All men think all men mortal but themselves.
Source: Night Thoughts. Night i. Lines 417-424
Contributed by: Zaady