Charlie was playing with his little brother Mickey when the little boy asked whether he could fly like Superman.
"Sure you can, Mickey," Charlie said, "Just flap your arms really *really* hard."
So Mickey climbed up on the windowsill, started flapping like mad, jumped, then smashed into the ground two stories below.
Horrified, their mother came screaming into the room and said, "What the heck happened?!?"
Charlie said, "I was just teaching Mickey not to believe everything someone tells him."