This is so so true ... I've been doing 4.5-5.5 hour nights (sleep) for years and very recently have started to see the effects in aging ... greying and balding at a much earlier age than I anticipated (for example). I've made my peace with it now, but I can't help but wonder how much I would have cheated aging if I had been sleeping 7/8 hours a night instead.

More scary is how much of the detrimental effect of lack of sleep I am yet to encounter.