I read this mainly because it had begun to feel a bit weird that I hadn't, given the shadow it casts across various stretches of popular culture. Having been found in the pocket of the bloke who murdered John Lennon, and then again in the fictional narrative of Margaret Thatcher's aspiring assassin in Grant Morrison's St. Swithin's Day, I'd always assumed Catcher to be about a neurotic outsider who flips and consequently pops an innocent with a firearm - the blueprint for all those school shootings. Thankfully it isn't anything quite so obvious and the general concept of both teenagers and their inherent disgruntlement was still very much in development back in 1951.
So Holden Caulfield isn't the tidily modular rebel who rejects whatever you've got on principle, but rather is someone who has failed to connect with aspects of his own existence - like a more freewheeling version of Roquentin from Sartre's Nausea, the first English translation of which had appeared just two years earlier, it might be noted. My own stepson had a couple of years at one of those supposedly prestigious military academies to which Americans with too much money send their offspring, and so I recognise Caulfield's environment, finding it both reassuring and depressing that someone else identified the exact same problems with such places over seventy years ago. Caulfield isn't a bad student, or a kid with any psychological issues which would today be medicated to drooling oblivion. It's simply that he's just smart enough to recognise bullshit when he sees it and struggles to reconcile himself to what is expected of him, most of which is predicated on the existence of a noble world full of grand achievements, aspirations, and fine men delivering speeches in front of marble columns, as distinct from a world made entirely of bullshit. He's been taught to hold truth as among the highest of virtues and so cannot help but revolt against that which it reveals. In practical terms, this amounts to his dropping out of school and vanishing off into the wild, blue yonder over the course of a weekend, as told in rambling first person with endless digressions and passing distractions in Caulfield's own distinctive if occasionally limited turn of phrase. You might argue the case for it being a more populist Nausea with Caulfield, lacking Roquentin's philosophical rhetoric, obliged to define his disconnection in more familiar terms, or terms with which I was more familiar at least.
It isn't a literary precursor to Ill Bill's Anatomy of a School Shooting, despite the reputation, being concerned with cause more than dramatic effect, and I doubt it would have endured so well were that the case.