" Otherwise, his desk is immaculate. In accordance with the four Ds of his system, everything that has not been done, delegated, or dropped has been deferred to a half dozen two-drawer file cabinets, which contain his alphabetized plastic folders with labels printed by the little machine next to his computer. You might dismiss this all as evidence of dreary anal-retentiveness, but Allen could not be less dour or more relaxed. "

― Roy F. Baumeister , Willpower: Rediscovering the Greatest Human Strength