Is it normal to memorize stories to tell yourself when going to sleep?

Maybe? It might be indicative of an anxiety disorder if you can't quiet your garbage factory while you're trying to sleep. I'm pretty sure normals just...sleep.

But I do the same shit. My trick is picking random letters from the alphabet and naming as many animals as I can that start with that letter...

B:
Brown bear, black bear, blue whale, blue footed boobie, blob fish, barracuda (good one!), bandicoot, bobcat, baboon...

It works

I do stuff like this. Try spelling out numbers in Roman numerals as you drift off. It's fun.

I don't know if it's "normal", but it's great if it helps you fall asleep. I can't sleep if it's pitch black or if it's quiet in my room.