Early on in the book it is made clear that Holden doesn't deal well with his brother's death. In fact, it says that he slept in the garage that night and in doing so, he busted out all the windows inside it. However, this might be expected. Allie was a constant figure in his life. They hung out all the time and not once did Holden ever say a negative thing about Allie so naturally when this constant figure in his life is suddenly taken away from him Holden only knows that this change is not acceptable to him. So in return, he acts in this behavior.

Later on in the book the reader is able to view the museum just as Holden does. Holden likes museums. He likes the way that no matter how many times he leaves, he knows that when he comes back, everything will always be just as it was before. This too is a constant in his life.

The ducks play an important role in Holden's view on change. The fact that these creatures come and leave doesn't sit well with him. This is showed when Holden talks to the cab driver about the ducks and when Holden goes looking for them in Central Park. Holden is disturbed that they aren't a constant for him.

Looking at his inability to cope with Allie's death, his liking towards museums and his infatuation with ducks, it is easily seen that Holden Caulfield doesn't deal well with change. To him, if nothing changes, there is no need to grow up which sounds great to him because if you don't have to grow up then you wont ever become a phony. This is the only way Holden knows to protect himself from becoming a phony like the rest of the population.