Dentist asks the guy what is the problem.
Guy says, "I'm a moth."
Dentist says, "You're a moth?"
Guys say, "Yes! I'm a moth. I act like a moth. I think like a moth. I'm a moth!"
Dentist says,
"Sir, I think you want the psychiatrist’s office. He's two doors further down the hall."
Guy says,
Spoiler: