There's a website called TV Tropes that has a trope called "Heroic BSoD", which means a hero has an emotional breakdown.
Because of this, I thought BSoD was a disorder, like OCD or PTSD, that meant you were prone to emotional breakdowns.
Later, I learnt that it's actually an abbreviation for Blue Screen of Death.
A childhood belief about speaking

others believed things like this
- My sibs and I thought that the screen door was called the "scream door" so Mom could yell at us through it. — Kyle
- I believed that the breed of dog called Boxer was called that because they could stand up and box.Anon
- I always thought you could break through the tv screen and walk into whatever was on the screen at the time.— Linda
- I used to believe that people from Holland were called "Hollish", like people from Poland are called "Polish"— Sally
- I used to think that adult kangaroos were called Kangas and that child kangaroos were called Roos. Anon
- I used to think that because there was a state called Washington, there was also a state called Dryington.— Jasonchic