What Are Some Strange Things You Believed To Be True As A Kid?

When I was little, I was always taught that if I bite my nails or knuckles, it would make me sick.  A friend of mine was recently talking about how they had their little brother convinced that water towers actually held gummy bears.  It's amazing the things we believe when we're kids only to find out when we grow up that they're ridiculous.

How about these ones:

• "If you keep you keep scowling, your face will freeze like that forever!"
• "If you swallow watermelon seeds, a watermelon tree will grow in your belly"
• "If you swallow your gum, it will stay there for 7 years."

What were you gullible enough to believe when you were a kid?