When I lived in London I was much more of a night owl, but then again I was going out a lot more and had, er, a social life. I've sometimes thought to myself how surprised my London self would be at how early I sometimes get up: the other day I was in Morrison's car park at 7:45am to do my weekly shop, as I couldn't sleep in the heat, so just got up.
I, too, need a totally dark, totally silent bedroom to sleep, but (unlike sunnydave, it seems!) I have no problem if I have to get up for a pee in the night: I don't have to put on any lights, or even wake myself up properly as at home I always sit down to pee. Often thought of starting a thread on men sitting down to pee - why would you not in your own home? Much more comfortable! The Germans even have a word for it : sitzpinkeln