Brief Wondrous Life... - Lessons

During the course of the book, many of the characters try to teach Oscar many things—especially Yunior, who tries to teach him how to lose weight, how to attract women, how to behave in social situations. Do any characters not try to teach Oscar anything, and just accept him as who he is? How much does Oscar actually learn from anyone? And in the end, what does Oscar teach Yunior, and the other characters if anything?