Does Holden  not fit in with the world around him? Might we speculate that Holden's "not fitting in" may be completely in his head? All indications seemed to prove that Holden had little trouble fitting in, while he had big trouble dealing with fitting in.
    We might feel right away that Holden is not getting along with his classmates when he appears alone at the football game. However, a safe summation of Holden's few days would show that he decided when he wanted to be alone, not others. This would lead to the conclusion that he may have felt that he did not fit in, while others did not feel that way.
    We must also wonder why so many well-adjusted and happy people can identify so frequently with Holden's observations. He feels that his friends are phony, yet he says little to them about it, thus hiding his feelings and being phony.
    His terrible grades certainly seem to indicate that he does not fit in, yet that is most likely just a means of trying to convince himself that he does not fit in. We can almost infer that what frightens Holden most is that he actually does fit in. All the swearing he uses is a prime example. He is set against little kids learning  to swear, yet he does it quite often. He realizes that he does fit in, but fitting is not good, so he wants to protect the innocence of the children.
    Holden also likes to kid himself that he does not fit in because he is not a pervert, but he seems to classify a few too many people as perverts, and even admits that some of the "perverted" stuff could be fun, especially if you're drunk. Ah, drinking! Is he trying to fit in by drinking, or trying, once again, not to fit in? Neither. Drinking is just another factor that causes poor Holden to fit in involuntarily.
    Sure, Holden is caught up on innocence and his brother Allie and all, but that does not cause him not to fit in , only to wish he did not. We can all see thing Holden's way, and we all do fit in, at least in other people's minds.  
    Does lying all the time cause Holden to not fit in? Au contraire! His lying seems to cause others to think of him as someone who fits in even better than he does. He doesn't want the kid's ma to think he doesn't fit in, or the nuns, so he lies to them. Lying to make yourself fit in better is a sure sign that you do fit in, because everyone wants others to believe we fit in just fine, including Holden.
    Holden may detest growing up, love innocence, dislike phonies, hate school, think the world is on the verge of collapse, and even think he does not fit in .... but don't we all?