All who joy would win Must share it -- Happiness was born a twin.

The couplet argues that joy is not a purely private possession: to “win” it, one must “share it.” Byron frames happiness as inherently relational—“born a twin”—suggesting it comes into being most fully in companionship, sympathy, or generosity rather than in solitary self-satisfaction. The epigrammatic form reinforces the moral: joy multiplies when distributed, and isolation diminishes it. Read in a Romantic context, the lines also echo a broader preoccupation with the social nature of feeling and the insufficiency of individual experience without human connection.