The greatest thing in life is to die young — but delay it as long as possible.

The line is a paradoxical witticism: it praises “dying young” not as an early death, but as retaining youthfulness—curiosity, flexibility, appetite for change—into old age. The second clause (“delay it as long as possible”) flips the apparent meaning, revealing the real counsel: live long, but do not become spiritually or mentally old. In Shaw’s characteristic style, the joke carries a moral edge, mocking complacent aging and urging continual self-renewal. The aphorism also plays on society’s romanticization of youthful vitality while insisting that the true achievement is sustaining that vitality across a long life.