How to solve a strange logic problem (seen in a joke)?

"You are 44 years old this year!" Student petrie answered.

"Hey, you are absolutely right." The professor praised: "Then please tell the class how you judged."

"That's not easy! I have an uncle who is called a half freak. He is just 22 years old this year! "

This is the second half of the joke. Reference:/Zhang Shengwen/blog/item/6545c317c6012609c83d67.html.