Johnny Teaches How To Become Superman

Little Johnny was playing with his little brother Mickey when the little boy asked whether he could fly like Superman.

"Sure you can, Mickey," Johnny 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 six stories below.  Horrified, their mother came screaming into the room and said, "What the hell happened?!?"

Little Johnny said, "I was just teaching Mickey not to believe everything someone tells him."