Ok so I saw this on a Private Server forum once, and what it is is that someone makes a wish and another person says something to make the wish useless. Example:
Wish: I wish that I was the fastest reader alive!
Other person: Granted. Your eyes just got gouged out by a bear.
Example 2:
I wish I had a cookie.
Granted. Your mouth just got sown shut.
Well, they don't have to be as violent as mine, but I bet you get the idea!
Okay, so now to start it off:
I wish that I was a ninja!