The fact that people say you should get 8 hours of sleep a night really is an average. My husband for instance continually amazes me be cheerfully hopping out of bed, eating breakfast, dressing in a color coordinated outfit, feeding the cats, brushing his teeth and washing his face plus occasionally showering and shaving before leaving for work. I, on the other hand, with an equal amount of sleep barely manage to assume a mind over mattress vertical orientation after the 3rd snooze button session, eating no breakfast, and wake up at my desk 20 minutes after leaving my pillow wondering who let me out of the house in that outfit and grateful that I at least have something on both my top and bottom and wishing that I kept a hairbrush and toothbrush at work, not to mention makeup and a spare outfit.
There will always be people who can live with 4-8 hours a night and "not only walk the following morning, but also make remarkably informed fashion decisions; and those of us who need "eleven" or more hours of sleep if we even hope to fall successfully onto the wooden floor beside the bed." as Dooce says.
Like Dooce, I remember taking kindergarten naps. The other kindergartners would bring balls to throw back and forth during nap time, eager for the time when they could all hop up and begin doing kindergarten things again. I on the other hand could completely zonk out and get some real rest during that time. My husband falls into a whole other category. I imagine him lying on the mat in kindergarten, his teacher shaking him awake, wiping the drool off of his face and creating a complete zombie for the rest of the afternoon. He may be able to fully function on only 6 or 7 hours of sleep instead of my 9-11 hours, but that man just isn't cut out for napping. As much as he may whine about wanting a nap I know its better to just send him packing to bed, because if he naps he'll be a zombie for the rest of the evening. Amazingly enough the man can sleep on planes like a baby whereas I, who fly 150,000 miles a year, can't sleep at all. I guess there are trade-offs. Wouldn't want both of us to be the same way, we would either never both get to work on time in the morning or both walk around airports like zombies unable to string a sentence together.