Reminds me of another joke:
There is a man who has been suffering from terrible, blinding headaches for years. He's seen doctor after doctor, but to no avail. Finally, he finds a doctor who says he can help.
"We don't know why this works," says the doctor, "But the only solution is to cut off your balls."
The man finds this unacceptable, and leaves the doctor's office dejected. But as he endures week after week of continued and worsening headaches, he begins to think that life wihout balls might not be such a bad option after all. So he returns to the doctor, and the procedure is performed.
Afterward, he feels like a new man. The headaches are completely gone, and he feels wonderful. He decides to celebrate by going on a shopping spree. At the menswear store, he is fitted with a new suit. He decides to buy new underwear as well, and picks a package off the shelf.
As the salesman is totalling up the bill, he notices that although he has just fitted the man with size 34 trousers, the underwear the man has selected is only a size 26. The salesman points out the mistake to the customer.
"Oh no, its not a mistake. I've always worn size 26 briefs," replies the man.
"Are you sure?" asks the salesman. "That can cause horrible headaches, you know." | 
