Youtube videos would have comments like "if you don't do xyz a girl with no face will kill you tonight". These were supposed to be commented to other videos. I was ten years old but I believed these! Then I remembered reading a book where a child called his stuffed animals the "dream police" which would keep him from having bad dreams. I tried this and of course it worked. I stopped panicking when I remembered the dream police.
Some of these YouTube comments started with "Please don't read this." For a while I actually stopped reading at that point (to follow directions lol)
In later years, I low-key believed those "repost or something good/bad will happen to you" posts online.
A childhood belief about i'm different

others believed things like this
- I used to think the old BBC logo that was on one of my videos as a child was evil and wanted me to be dead.— tanukibear
- I thought the song "Karma Police" was actually saying "call the police" before I learned the title— Alberto Richardson
- When I used to see the sign 'police accident' I thought it meant that a police car had crashed.Anon
- I though the "D" written in "Walt Disney" on some videos was actually a backward "G".
— A. Nonymous - when i was little i used to think Americas Funniest Home videos was fake— wendy
- I used to think that the police didn't know that we called them coppers behind their backs!— Chris