here is a quote from the wikipage:
"
Possessions meant little to Erdős; most of his belongings would fit in a suitcase, as dictated by his itinerant lifestyle. Awards and other earnings were generally
donated to people in need and various worthy causes. He spent most of his life as a
vagabond, traveling between scientific conferences, universities and the homes of colleagues all over the world. He earned enough in stipends from universities as a guest lecturer, and from various mathematical awards to fund his travels and basic needs; money left over he used to fund cash prizes for proofs of "Erdős problems" (see below). He would typically show up at a colleague's doorstep and announce "my brain is open", staying long enough to collaborate on a few papers before moving on a few days later. In many cases, he would ask the current collaborator about whom to visit next.
His colleague
Alfréd Rényi said, "a mathematician is a machine for turning
coffee into
theorems",
[16] and Erdős drank copious quantities (this quotation is often attributed incorrectly to Erdős,
[17] but Erdős himself ascribed it to Rényi
[18]). After 1971 he also took
amphetamines, despite the concern of his friends, one of whom (
Ron Graham) bet him $500 that he could not stop taking the drug for a month.
[19] Erdős won the bet, but complained that during his abstinence, mathematics had been set back by a month: "Before, when I looked at a piece of blank paper my mind was filled with ideas. Now all I see is a blank piece of paper." After he won the bet, he promptly resumed his amphetamine use."