A blonde's redhead decides to show her a neat way to trick people -- you put your hand on a wall and ask someone to punch it. But before they do, you pull your hand away!
"That is a neat trick," thinks the blonde, and tries desperately to remember it, but isn't all too successful. Despite this, she decides to try it out on her blonde friend.
"Okay," she says, "I'm going to put my hand in front of my face..."