I used to believe that doing the sign of the cross opened a connection directly to God. Sometimes, in my prayers, I'd forget whether or not I "closed" the connection, so I'd do the sign of the cross twice quickly hoping that that somehow reset the connection and I could go on thinking normal, sinful thoughts.
A childhood belief about prayers

others believed things like this
- when I saw a sign with a deer on it I always thought deer had to cross the street by it. like a cross walk— only me
- I thought for the longest time that a No Standing traffic sign meant no person should stand near that sign.— Shannon
- I thought that the "don't walk" sign at crosswalks meant to run across the street as quickly as possible!— richard
- When I was little I though "A Cross" was a mud/tar pit and that Jesus drowned.— Usagi Ohkami
- If you cross your eyes, they will get stuck like that.Anon
- I used to believe Nuns are a third gender, a cross between men and women:)Anon