Ron Graham Bet Paul Erdős $500 He Couldn't Go a Month Without Speed. Erdős Won.
The mathematician Paul Erdős quit amphetamines for 30 days on a $500 bet with Ron Graham, then restarted. What the bet did and did not change.
“You’ve set mathematics back a month.” That is the line Paul Hoffman’s biography The Man Who Loved Only Numbers attributes to Paul Erdős after he won. The bet was Ron Graham’s: $500 that Erdős could not go 30 days without amphetamines. I have the exchange through later retellings, and details vary among them. The outline does not: Erdős quit for the month, collected, and went back to the pills right after.
Notice what the bet contained. It had a skeptic on the other side, a fixed length, and a sum of money. It did not contain day 31.
That gap is the thing to copy and the thing to watch. A bet with an end date measures a month, and it will probably produce one. The finish line that makes it winnable also tells you when to stop. For a lasting change, schedule the next bet before the first pays out, and pick someone who will hold you to it. The research on paying people to keep a promise points the same way: a contract works while it is in force.