I’m not sure why, but I picked up a LOT of superstitions from various books I read. I was petrified of things like stepping on cracks, walking under ladders, black cats, and I tried my hardest to hold my breath through tunnels and while passing cemeteries.
They were all passing phases, but when your family doesn’t really do anything in the way of tradition, they appealed to my overactive imagination.
Oh, and I believed there were trolls who would eat me at night if I wasn’t careful. For protection, I had to sleep with my head almost completely covered by a blanket. Only my nose peeped out to breathe.

That was the result of seeing a movie (I think Troll 2?) way, way too young. It’s one of those horror movies that’s so bad it’s good, but very young me was very scared by it. I still get this terrible crawling feeling whenever someone mentions it.
(And I could not sleep without my head being covered until I was well into my 20s.

)