grandma like tendencies

For most of my adult life (18 to present) I have gone to bed at a decent time. Some might even go as far to say that I have crossed the line of decent into strangely early. But that is my routine and that is what works for me.
That is until about 3 days ago. For the life of me I cannot sleep. At present it is 11:32, not late, but not early for someone who regularly likes to be asleep by 10:15.
I have cut out afternoon naps, I am waking up early, and I cannot do anything about it.
I guess I may have taken sleep for granted. Usually within minutes of hitting the pillow I am out like a rock and I do not wake up until morning. And that's just how it's always been ... or at least that is how it's been for as long as I can remember.
And now I am tired, but I know that once I put my head on my pillow, something in my brain will just click and I will lay there for at least a couple of hours.
Given I have some things on my mind. But I don't think it's those things that are keeping me awake. I dwell enough during the day that I have no need to think at night.