• Me – It’s weird (or “Teeth will rot”).
• X – Then go to a dentist.

My informant claims he had created this joke himself.  Nonetheless when he used it on others, they were not surprised saying they have heard the joke before.  Perhaps he did originally think of the joke but others also thought of it simultaneously.  This joke is a play on words.  To say, “It’s weird,” in Korean uses the exact same wording as saying, “Teeth will rot.”  He thought of the joke when he misinterpreted his wife.  While she was stating that something was weird, he took it as her saying that she had a toothache.  Without paying close attention, he advised her to go to the dentist.  Upon hearing such an arbitrary piece of advice, his wife understood his misinterpretation and laughed at him.  Ever since then, which was about a decade ago, he tells a person to go to a dentist if he or she says something is weird.

“It’s weird” and “Teeth will rot” are not just similar; they sound and are spelled exactly the same way.  It is easy to see why someone may accidentally misinterpret the two meanings.  Misinterpretations can be hilarious, so it is not wonder this turned into a joke with several people thinking of it at the same time.