I too am beyond 30 but shy of 40.... for now. I'm not sure if there are gender issues involved, but I do think that this novel resonated with me as a kid because of the whole, "older people are all phony" aspect. If I read the book now, would that ring less true? Perhaps it would. I remember reading that the book was a favorite of John Lennon's assassin, Mark David Chapman to the extent that he wanted to legally change his name to Holden Caufield. He had thought Lennon was "selling out" and becoming "phony" etc. Apparently John Hinkley, the guy that shot Reagan was also a fan. I don't recall too much detail about the novel as it's been over 20 years since I read it. I recall him being at a turning point in life where he is expected to be acting more "adult" but he still very much feels like a kid. He has a little sister in the book which he seems to really love and he wants her to remain a "kid" very much. I think if I read it now, I would think he was a little shit. I guess I'm a sellout now.
I am impressed with your recall abilities. I vaguely remember the connection between the story and the deranged behaviors of Chapman and Hinkley. Because you mentioned Holden's sister Phoebe, it occurred to me that she, along with his friend Jane, appear to be the only glimmers of light in his life. Perhaps the message that Salinger tries to highlight, through a young person's point of view, which at times can be gross, is that, to some degree, most people are "little shits" that eventually become, in some respects, "big shits". In other words, he attempts to expose the imperfections of human existence with which we all must contend. Thanks for the insight. I will finish the work and let you know how I feel about it thereafter. Have a nice day!