Sleep Apnea Sleep, why do people sleep at all? Why can't we just stay awake? Some biologist suggest that sleep provides the opportunity to conduct self-repair and purge the body of it's waste that has built up during the day's activity. Nevertheless, the body is capable of repairing itself and disposing of wastes during waking hours, so sleep in a way really isn't necessary for routine maintenance (e.g., urinating, etc.). Dr. Quentin Regestein, lead sleep and sleep disorders researcher at Harvard Medical School also believed that sleep kept our distant ancestors out of harms way during the night when they could not see as well as their night roami