What did ponyboy do in the hospital that made his brothers yell at him for doing?

In the hospital, Ponyboy refused to follow his brothers' advice and insisted on reading "Gone with the Wind," which they thought was too much for him given his condition. They were concerned for his health and emotional state, fearing that he was overexerting himself after the traumatic events he had experienced. Their yelling stemmed from worry and frustration over his defiance and determination to act like nothing was wrong.