When I was little-little (3? 4?) way back in the crime-drama-and-violent-cartoon-filled 70's, I used to completely and utterly believe that if you laid down with your arms straight out to the side and your legs slightly spread (think classic "dead person pose"), and then closed your eyes and stuck your tongue out the side of your mouth, you'd drop dead instantly. I thought that when someone "died in their sleep" it meant that they had accidentally posed the death pose while they were asleep, and died. I was TERRIFIED that I'd do it to, so I started sleeping on my stomach. (For some reason, I believed the pose only worked if you were on your back.)
To this day (many, many, many years later), I still sleep on my stomach.
A childhood belief about people

others believed things like this
- I was told that if you sleep on your back you swallow your tongue...I have been sleeping on my side ever since— scotty la
- I used to think that all people closed their eyes and stuck their tongue out when they died.Anon
- I used to believe that when you died no matter what your tongue hung out the side of your mouth. Anon
- i used to believe that my nose could pose— charlotte
- I used to believe that you had to have your eyes closed and your tongue sticking out for you to be dead! — pinkgreencrazy
- I used to only sleep on my back because I thought I would break my ribs if I slept on my stomach.— Molly