Finally, one day, the doctor asks Mr. Johnson to undress. After inspecting Mr. Johnson’s body, he sees the problem.
“You have an extremely rare condition,” explains the doc. “Your testicles are pressed up against your spinal cord, giving you headaches. This condition has no known cause and only one known cure: castration.”
Determined to get rid of his headaches, Mr. Johnson agrees to get castrated.
When he wakes up from his surgery, Mr. Johnson is so relieved that his headaches are gone that he decides to go clothes shopping at a store to which he’s never been before.
He enters the store and says to the clerk, “I’d like to buy a new shirt, please.” But before he can tell the clerk his shirt size, the clerk has already produced a shirt.
Mr. Johnson inspects the shirt closely. Much to his amazement, the clerk has gotten all the measurements exactly right.
Then Mr. Johnson asks for a new pair of pants. The clerk gives him a pair of pants, and once again, he gets all the measurements exactly right without Mr. Johnson telling him anything.
Next, Mr. Johnson asks for a new pair of shoes. The clerk gives him a pair of shoes, and sure enough, they are in exactly the right size.
“This is all well and good,” says Mr. Johnson, “but now I challenge you to give me the right pair of underwear.”
When the clerk gives him the underwear, Mr. Johnson smirks. “Now that’s the first thing you’ve gotten wrong!” he says. “I wear a size M, not a size L!”
“Are you sure?” asks the clerk. “Because it looks to me like a size M would press your testicles against your spinal cord and give you an awful headache.”