Sara Teasdale’s speaker looks ahead to old age and imagines it as a kind of emotional numbness. The moonlit water that once seemed painfully beautiful—stinging “like silver snakes”—will no longer wound her, because the years will make her “sad and cold.” At first that sounds like loss, but the central insight is paradoxical: “It is the happy heart that breaks.” Feeling deeply means being vulnerable. The heart asks more than life can give, and once a person learns that, the glittering waves lose their power to hurt. Beauty itself is fugitive, but so is the sting of wanting it. The mood is wistful and resigned rather than bitter. By repeating the opening line at the end, the speaker turns it into a quiet consolation.
Moonlight — Summary
It will not hurt me when I am old, A running tide where moonlight burned Will not sting me like silver snakes; The years will make me sad and cold, It is the happy heart that breaks.
The heart asks more than life can give, When that is learned, then all is learned; The waves break fold on jewelled fold, But beauty itself is fugitive, It will not hurt me when I am old.