A childhood belief about fear of

I used to believe that when you flushed the toilet, you had 5 seconds to get out of the bathroom and onto a piece of furniture, or a monster would come and get you. A few years later, I saw some alien movies and thought if I sat on the toilet too long, an alien hand would reach up and grab me from inside the toilet bowl. Needless to say, I would stare at the water EVERY time I went to the bathroom, just in case I saw something move in there.