Where It All Goes Down
Princeton and New York City
No matter where you are in this book, Fitzgerald tends to describe his settings in the same poetic language. The reason he does this is straightforward: his main character Amory only notices the world around him when he's thinking deeply about his life.
As we read at the end of the book, for instance,
Long after midnight the towers and spires of Princeton were visible, with here and there a late-burning light—and suddenly out of the clear darkness the sound of bells. (2.5.245)
Pretty much all of Fitzgerald's descriptions of setting appear in this same deep, meditative tone, since they always come hand-in-hand with Amory having deep thoughts about love, life, and success… or the lack thereof.
The symbolic importance of the locations of Princeton and New York City haven't changed much since Fitzgerald wrote This Side of Paradise. Princeton is a crazy-prestigious school—almost always ranked among the top three universities nationwide. If you want to be a mover and a shaker, going to Princeton is a good move (and shake) to make as a young student. Amory gets in to Princeton, but he finds that he can't finish—he just doesn't have the academic rigor to graduate.
New York City serves a similar purpose. New York is an infamously hard place to get ahead—Sinatra tells us that "if you can make it (there) you can make it anywhere" and Jay-Z knows that "out there in the naked city it's a pity half of y'all won't make it." It's basically the Princeton of cities: tough. And what happens to poor ol' Amory? The same thing that happens to him at Princeton. He gets in (you don't have to ace the SAT to get into New York City, after all)… but he can't make it in the naked city, and leaves with his tail between his legs. Womp womp.