Why does Junior feel trapped between the Indian and white world?

Junior's main struggle over the course of The Absolutely True Diary of a Part-Time Indian is between his cultural ties to the reservation and his ambitions to educate himself and achieve a better lifestyle than most of the members of his tribe. He faces resistance on all sides: Rowdy and many other people on the reservation call Junior a traitor, even turning their backs on him during a basketball game. Meanwhile, Junior's Reardan classmates either ignore him or torment him for being different. He does not feel as though he fits into either place, hence the title "Part-Time Indian." However, Junior eventually discovers that he does not have to mold himself into a preconceived notion of what an Indian or a white kid is supposed to be like. Many share his struggle, he realizes, and thinks to himself, "I might be a lonely Indian boy, but I [am] not alone in my loneliness" (217).