One of the most significant themes in Catcher in the Rye is Holden's loss of innocence. Holden, as the novel progresses, shows a lack of innocence and an introduction to the "real world". Holden attempts to grasp back at his previous innocence as a base for his emotions. There are various symbols and events throughout the novel that discuss Holden's loss of innocence.
One of the most significant of these is the glove belonging to Holden's deceased brother, Allie. This glove reminds Holden of his youthful fruitfulness and his unending love as a child. As Holden matures and enters adolescence he begins to lose this sense of love. The fact that he went to a boarding school may have contributed to this loss of love due to the fact that he was surrounded by phonies. He starts out the novel by saying "If you really want to hear about it, the first thing you'll probably want to know is where I was born, and what my lousy childhood was like, and how my parents were occupied before they had me, and all that David Copperfield kind of crap, but I don't feel like going into it, if you want to know the truth."
This statement was said when he was in a medical center, after the story took place. He does not want to discuss his loving happiness as a child, rather he discuss his downfall in life. He acts as if he is afraid of his previous innocence and doesn't like to reflect back upon it.
Another example of his innocence would be his interest in the ducks at the pond. He cares about those ducks and consistently asks people about what happens to the ducks in the winter. Despite the fact that probably nobody would...