Childhood sometimes does pay a second visit to man, youth never.

Jameson contrasts two kinds of return: the possibility of recovering a childlike state—wonder, simplicity, play, or dependence—versus the irrecoverability of youth as a life-stage defined by physical vigor and forward-looking promise. The aphorism suggests that later life may circle back to certain childhood qualities (through nostalgia, renewed tenderness, or even the vulnerabilities of age), but it cannot truly recreate youth’s particular mixture of strength, novelty, and open future. Implicitly, it warns against mistaking late-life sentimentality or “second childhood” for genuine youthfulness, and it invites readers to value youth while it is present rather than assuming it can be regained.