A man repeatedly asks out a beautiful young woman he works with. She
says no at first, but finally agrees. "You can pick me up at eight
on Friday," she says, "but you have to bring me a pocketknife."
"Well, okay," he says, puzzled.
Friday night comes, and he arrives at her house with a pocketknife.
She thanks him, opens a drawer in a desk which is already full of
pocketknives, and drops the new one in.
At the restaurant, the man's curiosity finally gets the better of
him. "I'm sorry, but I have to know. What's the story on these
pocketknives?"
She smiles at him and answers, "I know that you men ask me out just
because I'm pretty. I know that in twenty years my looks will be
gone and men won't be interested in me anymore. But I also know
that there's nothing a fifteen year old boy won't do for a
pocketknife."