A childhood belief about fear of

When I was about five or six, I was at the video store with my mother and as she was browsing I accidently came across the horror section and saw the cover of the film - I think it was 'Ghoulies' or something, anyway it has a sharped toothed green gremlin type thing coming out of a toilet. I couldn't get the image out of my head - just from a video cover. For the six or seven years, I had a fear of going to the toilet at night. If it was really urgent I would have to go through a ritual of turning on the light and checking under the toilet seat, and then ensuring that the door was firmly closed when I was finished, so I couldn't be visited by any green monsters in my room. I was terrified. It took significant effort to shake the feeling of fear right up until about the age of fifteen, even after I'd realised it wasn't possible to have monsters in the toilet.