Ponyboy has always been better in school than Johnny, and he is surprised that Johnny can get so much out of a book.
After Johnny kills Bob, he and Ponyboy have to go on the run. They hide out in an abandoned church waiting for Dally. While they wait they kill time by reading Gone with the Wind.
Johnny sure did like that book, although he didn't know anything about [it], and I had to explain a lot of it to him. It amazed me how Johnny could get more meaning out of some of the stuff in there than I could… (ch 5, p. 76)
Johnny is slow, but not stupid. It takes him a long time to get a concept, but he likes to explore it to great depths once he has it. He enjoys discussing the book and the concept of the “Southern gentleman” with Ponyboy. Pony realizes that Johnny is very intelligent and sensitive when given time.
Growing up poor in an abusive household, Johnny never had much of a chance. He is a sweet kid and has a good heart, and turns out to also have a good brain. Pony finds it sad that Johnny has missed out on so much of his potential.