I was the same then I had kids and now I probably get 6-7 hours per night, and they're fragmented. Your body adjusts. You use caffeine more effectively. One big learning for me is that i blamed a lot of being tired on lack of sleep, when in reality there are other causes (ie a big or greasy mid-day meal, sugar/caffeine crashes, etc).

That said, i'm sure it has long term health consequences though.