I know a man who gave up smoking, drinking, sex, and rich food. He was healthy right up to the day he killed himself.

Cast as a deadpan one-liner, the joke skewers the idea that health is simply the product of self-denial. By listing classic “vices” (smoking, drinking, sex, rich food) and then undercutting the expected payoff—long life and happiness—with suicide, the line highlights a paradox: a life optimized only for bodily health can still be psychologically empty or joyless. The humor depends on abrupt reversal and on conflating “healthy” with “well,” suggesting that wellbeing includes meaning, pleasure, and mental balance, not merely abstinence. It also satirizes moralistic health advice by implying that purity can become its own kind of pathology.