If I wake up in the night and have to leave my bed, going to the toilet is an obvious example, it can take me a little while to get back to sleep again. When I was a kid (by this I mean child; not goat), I’d wake up and make a mental note of where I was positioned in bed, my warm spot. Then I’d get up do the deed and get back exactly into that warm spot again. I was so good at it that I could even tell if the duvet needed adjusting.
I would then fall asleep instantly.
Oh to get back to the state of mind where the first thing that pops into my head when I wake is how I’m lying, rather than ‘what time is it, will I have to get up soon, etc. etc’