I used to believe that the meaning of term "screw you" was "forget you" (or something like that) because, often when people are frustrated, they'll say "screw this!"
As a child, I had just broken up with my "first boyfriend." My "friend" liked him and was talking relentlessly about him one day. I soon became annoyed with this (my wounds still fresh) and responded to her: "Well, just screw him! I don't care anymore!"
She obviously knew the exact meaning of "screw" because she never talked to me again.
A childhood belief about swearing

others believed things like this
- when i first heard the name "blow job",i thought the meaning of that word was blowing a snot out of your nose.— myuka
- A friend on mine thought that smoking menthal cigarettes would make his breath minty fresh.Anon
- That people older than me knew what they were talking about.— Mark
- I used to believe all black people were named Fresh Prince. — Ashlyn
- when I was little, I used to think that everyone was a child but someone invented adults to take care of us.— chocolate
- I used to think that masterbating was a fishing term for people who fish really wellAnon