"Size 34 Underwear" joke

Joe was moderately successful in his career, but as he got older he was increasingly hampered by incredible headaches. When his personal hygiene and love life started to suffer, he sought medical help. After being referred from one specialist to another, he finally came across a doctor who solved the problem.
"The good news is I can cure your headaches... The bad news is that it will require castration. You have a very rare condition which causes your testicles to press up against the base of your spine. The pressure creates one hell of a headache. The only way to relieve the pressure is to remove the testicles."
Joe was shocked and depressed. He wondered if he has anything to live for. He couldn't concentrate long enough to answer, but decided he had no choice but to go under the knife.
When he left the hospital, his mind was clear, but he felt like he was missing an important part of himself. As he walked down the street, he realized that he felt like a different person. He could make a new beginning and live a new life.
He walked past a men's clothing store and thought, "That's what I need: a new suit." He entered the shop and told the salesman, "I'd like a new suit."
The salesman eyed him briefly and said, "Let's see... size 44 long." Joe laughed, "That's right, how did you know?"
"It's my job."
Joe tried on the suit. It fit perfectly. As Joe admired himself in the mirror, the salesman asked, "How about a new shirt?" Joe thought for a moment and then said, "Sure..."
The salesman eyed Joe and said, "Let's see... 34 sleeve and... 16 and a half neck" Joe was surprised, "That's right, how did you know?"
"It's my job."
Joe tried on the shirt, and it fit perfectly. As Joe adjusted the collar in the mirror, the salesman asked, "How about new shoes?" Joe was on a roll and said, "Sure. .."
The salesman eyed Joe's feet and said, "Let's see... 9-1/2... E." Joe was astonished, "That's right, how did you know?"
"It's my job."
Joe tried on the shoes and they fit perfectly. Joe walked comfortably around the shop and the salesman asked, "How about a new hat?" Without hesitating, Joe said, "Sure..."
The salesman eyed Joe's head and said, "Let's see... 7-5/8." Joe was incredulous, "That's right, how did you know?"
"It's my job."
The hat fit perfectly. Joe was feeling great, when the salesman asked, "How about some new underwear?" Joe thought for a second and said, "Sure..."
The salesman stepped back, eyed Joe's waist and said, "Let's see... size 36."
Joe laughed, "No, I've worn size 34 since I was 18 years old."
The salesman shook his head, "You can't wear a size 34. It would press your testicles up against the base of your spine and give you one hell of a headache."