In the highlands of Indonesia, the teeth of a hunter-gatherer who lived 25,000 years ago have yielded a quiet but profound revelation: chemical traces of betel nut, suggesting deliberate and repeated use of a psychoactive substance long before agriculture, cities, or written language. Scientists analyzing the dental calculus found not a single encounter but a pattern — a habit — pointing to botanical knowledge and intentional experimentation in the deep human past. The discovery invites us to reconsider what we thought we knew about when the human impulse to alter consciousness first emerged,