Why did the Headmaster summon Albert? What was the outcome?

Albert was quite fed up with the present school and the technique of education. He could not tolerate the insult done by his History teacher Braun. Albert got a medical certificate from Dr. Ernest Weil. Dr. Weil certified that he had a nervous breakdown and must stay away from school. Albert didn’t need this certificate. The next day the head teacher called Albert to his office. He told Albert that his work was terrible. Therefore, he was not prepared to have him in the school. Albert asked if he should think he was to be expelled. The head teacher told him that if he left the school of his own accord, the question won’t arise. Albert asked what crime he had committed. The teacher told him that the teacher couldn’t teach the class when he was in it. Also due to his presence, the students couldn’t learn. Albert wanted to tell the head teacher what he thought of him and the school. But he didn’t say anything. The head teacher asked him to close the door behind him. But Albert didn’t do so. Nor did he have the last look at his school. He only met Yuri and saw Mr. Koch, got the certificate and left Munich.