I'm partially retired, and always been a night owl. It's rare I have any commitments before 10 or 10:30 AM and work at home. And I always catch up on sleep over the weekend, so if I go to bed too early on a Sunday night, I just toss and turn. So I usually while making hot chocolate or something around 3 or 3:30 AM take a look, before getting 6 hours sleep, rather than the usual 7 to 8. And occasionally I just wake at 5 am or something with only 3 hours sleep, and walking around the house, raiding the fridge, and checking email, etc., I've found works better than just lying there.