I think that there is a really strong and debatable issue if Holden has changed as a result of what has happened. The ending of the book is ambiguous as to what actually ends up happening to Holden. As a result, we are not entirely certain if he has matured or evolved as a result of what has happened. Presumably, he will go back to another prep school back East, but there is little else offered to the reader if he will change or if this particular set of experiences have helped him mature. I think that in constructing his character in this manner, Salinger has developed Holden into a complex characterization. The traditional notion would be to force some level of false realization or revelation in noting that Holden would automatically mature or capitulate into a socially accepted understanding of "maturity." In leaving the issue of Holden's maturation as something that is not entirely clear, Salinger has been able to raise issue as to what society defines as "maturation" and what we, as readers, understand as maturation. In this, Holden's supposed "change" becomes as much a crucible for him as it is for us, the reader. In this light, there is no clear question as to whether Holden has matured as a characterization, and we are left to wonder what defines the concept in our own being and in our view of ourselves as well as Holden.