A boy was playing with his little brother and asked him whether he could fly like Superman.

"Sure you can," encouraged the older brother, "Just flap your arms really really hard."

So the little brother climbed up on the windowsill, started flapping like mad, jumped, then smashed into the ground just a few inches below.

Horrified, their mother came screaming into the room and said, "What is going on here?!?"

The older brother looked at his mother innocently and said, "I was just teaching him not to believe everything someone tells him."