I used to believe that if you stared in a mirror for an hour or longer and then backed away your reflection/and time would freeze. The only way to unfreeze it would be to get back in the same exact possition and stare for the same amount of time.
A childhood belief about mirrors

others believed things like this
- If you stare into a mirror in almost complete darkness, the devil will appear instead of your reflection.Anon
- I used to believe that when you cracked a mirror your reflection would come and take over your body!— XxXAbbeyXxX
- I used to believe that my reflection in the mirror was my evil twin that always had bad hair. XDAnon
- I used to think that if I stared at the sun for a long time, I could make day turn to night.— Big J
- I used to think I could sneak up on my reflection and catch myself not looking back at me.— Mary Poppins
- When I was little I was conviced if you said twinkee in a mirror 3 time a foot would appear. Anon