[nostromo]

I'm in my early 30s now, and I've noticed among my friends that the folks who aren't regularly getting enough sleep have seemed to prematurely aged. It's not one big noticeable thing, but it's lots of little things, like how good their skin looks, how much gray they have, what there energy level is.

Don't ask for sources, because I don't have any, this is just an anecdote and a hunch. :)

I'm in the fortunate position now of being able to set my own work schedule. I almost never use an alarm clock, but I still get up around 8am, which is my personal indicator that I'm sleeping enough. I've also found that I have no problem working 12 or 14 hour days, much more than your average worker, but when I do so, I never take the time away from sleeping, but other activities instead.