For me, I'm sleeping a lot less since I retired almost 5-1/2 years ago, (December 2014). I was never a heavy, long term sleeper. But since I retired, I find myself both going to bed, and getting up much earlier. Usually 4 to 5 hours of sleep does it for me. I have no set time for either going to bed, or getting up. I do it when I feel the need. If I get tired in the afternoon, I'll take a short nap.
I won't lay in bed awake. Instead I'll get up and start my day. I even put a TV out in my garage, so I can go out there and watch it if I get up in the middle of the night. (I'm hard of hearing, and that way I don't bother the dog or the old lady by playing it too loud). I actually like getting up very early, (12:00 AM to 2:00 AM). Especially in the Summer. It's the coolest, and the quietest time of the day.
My frame of mind is much better as well. I no longer have any of the bull$h!t at work to deal with. I never minded doing my job. In fact, I rather enjoyed it. But I hated all the politics and drama a lot of people always seem to make, that always manage to surround it. I think a lot of that is getting worse in many places today. Especially with women in the workplace. Anyway, I'm very glad I don't have to concern myself with it any longer.
Work on the "Man Cave" is an ongoing process.