Well, I get up at 0545 for school (I take the bus, and I live a fair bit away) but in general, I don't sleep for long periods: could go to bed at 2300 after a long play on the Xbox or PC, and wake up at 0600, not a bit tired, and go back to the video games...
I remember when I was a teenager - I could go to bed drop off and remain asleep until at least 6am the following morning. Now if I manage to go to sleep straight away and not have to get up to use the toilet or sip some water during the night, I feel like I've performed a miracle.