What gets skipped in class discussion: everyone in the novel is chasing something borrowed — a green light, a version of themselves they built out of other people's approval. Daisy isn't a villain so much as a mirror for exactly how far people will bend reality to keep believing in a story they've already told themselves. Tom isn't a villain either, not really — he's just someone who never had to build a version of himself in the first place, because the world handed him one at birth. That contrast is the actual engine of the book, and it rarely makes it into the classroom discussion, which tends to stop at "the green light represents hope."
Nick, the narrator everyone trusts because he tells us to, spends the whole novel insisting he's honest while quietly protecting people who don't deserve it. That's worth sitting with. We're taught to read him as reliable simply because he says so, the same way we're taught to trust a lot of narrators — in books and outside them — mostly because they sound calm while saying it.
It's less a novel about greed than about the impossibility of going back once you've started performing who you want to be. Gatsby doesn't want money for its own sake; he wants the five years back, and money is just the tool he's using to try to buy them. That's a much harder, sadder ambition than greed, and it's the one the book is actually interested in.
Worth rereading after you've actually wanted something you couldn't have — not a crush, not a car, but a version of your life that was already gone by the time you noticed you wanted it back. That's the reading this book deserves, and it's the one most classrooms skip in favor of a five-paragraph essay about the American Dream. The American Dream is in there, sure. But it's not the point. The point is what happens to a person who mistakes a memory for a future.