In the novel The Outsiders, what does Ponyboy learn about the way he has been acting?

In Chapter 12, Darry is arguing with Ponyboy about his bad grades and Darry tells Pony that he needs to stop acting like he doesn't care about his life. Sodapop is bothered by the fact that his relationship with Sandy is ruined and becomes sick of Darry and Ponyboy continually fighting. Out of nowhere, Sodapop runs out of the house. Darry and Ponyboy are shocked, and Darry holds up Sodapop's letter unopened. For the first time, Pony realizes that Soda has problems too. Ponyboy mentions that he had never really paid attention to Soda's problems because he took it for granted that Sodapop never had any.

Darry and Ponyboy decide to run after Soda, and when they finally catch up to him, Sodapop explains that he feels like Darry and Pony are playing tug-o-war with him. For the first time, Ponyboy realizes how it is hurting Sodapop to continually pick sides during arguments. Sodapop then tells Ponyboy that he needs to understand that Darry sacrificed a lot to keep the family together, and that Darry only wants what is best for him. Ponyboy finally realizes that Darry is only twenty years old and that he expected Darry to understand everything about himself. Pony feels ashamed for never trying to get to know Darry. At the end of the novel, Ponyboy learns that he was acting selfishly by not attempting to gain perspective into the lives of his brothers. He gains perspective into Sodapop's issues and becomes appreciative of Darry for his sacrifices.