Paul Hoffman's biography of Erdos : "Erdös first did mathematics at the age of three, but for the last twenty-five years of his life, since the death of his mo

Paul Hoffman's biography of Erdos : "Erdös first did mathematics at the age of three, but for the last twenty-five years of his life, since the death of his mother, he put in nineteen-hour days, keeping himself fortified with 10 to 20 milligrams of Benzedrine or Ritalin, strong espresso, and caffeine tablets. "[0] [0]: http://www.nytimes.com/books/first/h/hoffman-man.html http://www.nytimes.com/books/first/h/hoffman-man.html