scientifically speaking, How do people function on 6 hours of sleep?

No.11206883 ViewReplyOriginalReport
if i don't get 8 hours of sleep, the next day I experience concentration issues. I've noticed some people get 5-7 hours majority of their nights and seem "fine". btw, i'm not talking about a 1-3 all nighters a month, but having no trash daily sleeping habits for months on end.