[ivankirigin]

http://nostalgia.wikipedia.org/wiki/Paul_Erdos " His working habits became characterised by working obsessively long hours, sleeping at most 4-5 hours a night and relying on the heavy use of amphetamines to maintain his activity levels. Once a friend challenged him to give up his drug use for a month; he complied, but later complained bitterly that mathematics was held up for a month. "