Why did Curt Lemon insist on having a tooth pulled by the dentist?

In this instance, Lemon was facing his demons.... his greatest fear. After passing out when he entered the dentist's office earlier, he needed to rpove to himself that he could do it..... and he did it in a big way.

Curt Lemon experiences a dilemma. He was that super tough guy in the combat, but he becomes a frightful kitten on the dentist line. He manages to escape from dentist, however later he finds himself in a great regret. He feels that his masculinity was damaged because of his fear. When he goes back to dentist to heal him he has no pain. He insists to dentist to pull his teeth, after that he becomes normal without a regret.