I have figured out what my sleep problem is.
I have been trying to have a healthier diet. Due to some GI issues, a doctor suggested I have more probiotics. I’ve been doing this by consuming large amounts of yogurt, mostly Greek yogurt. (More protein.) At the same time, I’ve been cutting down on sugar. I started by reducing, a lot, the amount of Coke I drink. I used to drink one or two cans a week. Now I seem to be drinking that amount in a season. Or financial quarter.
To continue on with this, I’ve been reading nutrition labels to get an idea of how much sugar is in things I drink. I usually compare the drinks to a can of Coke which has a lot. And it is depressing how much sugar is in everything. Two mugs of hot chocolate have as much sugar as one can of Coke. So I’ve stopped having an afternoon hot chocolate at work.
I need something to drink that doesn’t have sugar. I don’t like coffee.
Then I hear about Kombucha. Miracle drink all the hippies like. It has probiotics. It doesn’t have sugar. I got a six pack on sale at Costco to try it out. I tried drinking it at dinner instead of something that would have had too much sugar. It doesn’t have the greatest taste, but it isn’t terrible.
And when I had some on Tuesday evening, I had trouble sleeping. The same as on Sunday night, when I also had a Kombucha.
A quick check of the internet. Yup. Kombucha is made from tea and has caffeine.
Did I mention I’m also trying to cut caffeine out of my diet?

The biggest problem I have when I wake up too early is to try and do what my body wants to do.
I can see I have a good hour and a half before I need to actually get up. I am sleepy. I want to sleep. I have no reason not to sleep.
Except I have to work at trying to sleep. And that is tiring. I have to force my brain to concentrate on sleeping. It is not easy to do, because you almost have to do the opposite of concentration. Probably some Zen hippy could describe it better than me. I usually give myself a mental problem to work on that will hopefully distract my thought process; My current favourite is to list the countries of the world, in order, by where they are on the coastline.
In any case, trying to stay in that mode of trying to sleep becomes too much after awhile. It is easier to just wake up and spend some time reading.
This does not solve the fundamental problem that everything wants to go to sleep.