Humans are no strangers to drug use. We’ve been blowing our minds out of our skulls for thousands of years. It’s just that we previously thought we waited a bit longer as a species before we dabbled in mind-expansion.

New research published in Science Advances suggests we can push the timeline of human drug use back by 3,000 to 12,000 years. Archaeologists studying the teeth of a hunter-gatherer who lived in Indonesia between 16,000 and 25,000 years ago found what may be the oldest evidence of humans deliberately seeking out a substance that brings on a psychoactive high.

Researchers found the teeth in Leang Bulu Bettue, a cave on Sulawesi. Their molars had unusually deep grooves, and researchers found traces of arecoline, the psychoactive compound in betel nuts, which hundreds of millions of people still eat today and have often used in social and religious practices.

25,000-Year-Old Teeth Reveal Ancient Drug Addicts Got Their Fix Sucking Nuts

Piecing together the evidence, the researchers think the forger probably sucked on the nuts to reap some kind of therapeutic effect, probably to use it as a kind of primitive painkiller. Little did he know that his habit may have actually made matters worse, as the act of chewing and sucking on the nut damaged his teeth so badly that he probably had to rely on the psychoactive substance to deal with the pain the nut was causing.

This poor ancient guy was stuck in a pain/pain killer feedback loop. It’s darkly funny. Long before modern medicine, ancient humans were already finding ways to manage pain and seemed to have learned that sometimes the cure can be worse than the disease.

Evidence also suggests these ancient humans didn’t just decide to chew on it for pain-killing effects. This may have been culturally transmitted knowledge, as another person who lived roughly 7,000 years ago, found in a nearby cave, had similar dental wear and tear, hinting that this was common knowledge shared across generations.