For as long as I can remember I've thought that there are people watching from behind fitting room / public bathroom mirrors. Someone told me this ridiculous trick to see if it's a "real mirror" or not... and even though I know it's preposterous, I still do the mirror check every time I'm in a room with a mirror. I'm 26!
A childhood belief about mirrors

others believed things like this
- when i was young i used to believe that my image on a mirror would come to life if i broke the mirror.Anon
- I believed that if I looked too long in the mirror admiring myself the Devil would appear.— Paul Elletson
- When I was little I was conviced if you said twinkee in a mirror 3 time a foot would appear. Anon
- I had a fear of seeing a person in the corner of the mirror(most of the time a morlock)— Shane
- I used to think that if a mirror with me in it breaks, I break.Anon
- I used to believe that there was a person in the mirror who looked exactly like meAnon