Physics Is Like Sex Sure It

This quip is attributed to Richard Feynman and is widely quoted, though no specific primary source — a documented lecture, interview, or letter — has been identified. Feynman's delight in the uselessness of pure science was genuine and often expressed: in The Pleasure of Finding Things Out (1981) he argued that science's value lay in its capacity to generate wonder, not in its applications. The sentiment reflects his characteristic blend of irreverence and deep seriousness about physics.