Random brainfart for your amusement.

Thinking about GMing, I often find that getting in the same kind of mental state as daydreaming is very helpful to "unclog" the mental pipes.
If the world is still existing and things are happening with or without the characters input, then the GM finds themself in a kind of computer's role of "running the simulation".
But honestly, to do it like a computer would be far outside a person's conscious capacity. Every tree chopped down, every visit to the outhouse, every coin spent in a town. Nobody got time for that.
So I let my subconsious handle that. I go into a daydreaming state and just think about the campaign for a while. What's happening that's cool? Is there a festival coming up? What the hell did that Ettin just eat? The good ideas actually get used, and the less useful ones go back into the mental hopper to cook for a while longer.

Anyone else do something similar?

I do think you are on to something here.

My best sessions tend to be a half-page of notes or so, and then "day dreaming" about what might specifically happen. Usually when I am doing something menial, like washing dishes.