Jerry keeps a poster in his locker with a quote from the T.S. Eliot poem, "The Lovesong of J. Alfred Prufrock". The poster reads:
"Do I dare disturb the universe?"
The question in the original poem relates to ambition, aging, and a sense of failing to find purpose in a particularly modern social world. In the novel, the question relates to Jerry's personal dilemma - to conform (for safety and popularity) or to "be himself".
Jerry chooses to maintain his individuality at all costs. He dares to disturb the universe. The lesson he learns from his experience is not as straight-forward or uplifting as one might expect to find in a young adult novel.
Being beaten bloody in front of a crowd of his fellow students as well as at least one teacher, Jerry learns that "they" don't want you to be yourself, even though they tell you they do.
"They don't want you to do your thing, not unless it happens to be their thing too." And more importantly he has discovered what happens if you try: "They murder you."
Belonging, then, can be seen as something of an antithesis to the stronger themes in the text regarding conformity, the challenges of being yourself, and the dangers of going against the group.