Isolation is a recurring theme within the novel built subtly through imagery and through the gradual evolution of Holden's mind through experience. Hints of the theme were depicted early in the novel, such as the lonely streets of New York, or when Holden is standing at the top of the hill watching the football game by himself, all the way to Holden taking this journey of what it means to be an adult and grow up on his own and figuring out the way of the world first hand. Salinger uses these events along with a plethora of others to teach us as an audience that the journey to self discovery is necessary but also lonely.
The most significant of these discoveries can be seen when Holden comes into contact with the prostitute. And with the innocence of child Holden wishes to just speak with the prostitute instead of progress further with her. But then Holden has to come to the cold realization of the greed and mindset of others. He pushes to live life independently like an adult but when the time comes Holden finds himself grossly unprepared both physically, and emotionally. Throughout the course of the novel Holden works on finding that ideal balance to build his life upon.