I've found that I require less sleep as I get older. If I get about 5 or 6 hours each night, that's enough. I also remember that I had to drag myself out of bed in the morning when I was younger after getting the 'recommended 8 hours' that we always hear about.
I get up at about 5-5:30 am every day after going to bed around midnight. It's much easier for me these days and I feel better during the day than if I were to get 8 hours or more.
I'm most creative early in the morning but sometimes I have inspiration late at night and work until about 3 am. Even then, if I get a few hours sleep I do well for the rest of the day.
I don't have sleeping problems. I just like to be awake for more hours than I used to.
Mick