Erdos liked to work in short, intense collaborations with other mathematicians, and he crisscrossed the globe seeking fresh talent, often camping out in colleagues’ homes while they worked on a problem together. One such colleague remembered an Erdos visit from the 1970s: … he only needed three hours of sleep. He’d get up early and write letters, mathematical letters. He’d sleep downstairs. The first time he stayed, the clock was set wrong. It said 7:00, but it was really 4:30 A.M. He thought we should be up working, so he turned on the TV full blast. Later, when he knew me better, he’d come up at some early hour and tap on the bedroom door. “Ralph, do you exist?” The pace was grueling. He’d want to work from 8:00 A.M. until 1:30 A.M. Sure we’d break for short meals but we’d write on napkins and talk math the whole time. He’d stay a week or two and you’d collapse at the end.
Erdos owed his phenomenal stamina to amphetamines—he took ten to twenty milligrams of Benzedrine or Ritalin daily. Worried about his drug use, a friend once bet Erdoos that he wouldn’t be able to give up amphetamines for a month. Erdos took the bet and succeeded in going cold turkey for thirty days. When he came to collect his money, he told his friend, “You’ve showed me I’m not an addict. But I didn’t get any work done. I’d get up in the morning and stare at a blank piece of paper. I’d have no ideas, just like an ordinary person. You’ve set mathematics back a month.” After the bet, Erdos promptly resumed his amphetamine habit, which he supplemented with shots of strong espresso and caffeine tablets. “A mathematician,” he liked to say, “is a machine for turning coffee into theorems.”
Daily Rituals: How Artists Work by Mason Currey