What happened to charlie in the book flowers for algernon?!?

i dont know what happened to him !!

What happened to charlie in the book flowers for algernon?!?
He "reverts" to his original state:


"Having regressed almost completely to his original state, Charlie returns to the Donner’s Bakery and gets his old job back. He refuses to accept money from Alice and Strauss. When a new employee named Meyer Klaus picks on Charlie and threatens to break his arm, Joe, Frank, and Gimpy come to Charlie’s rescue. They tell him that he should come to them for help if anyone ever gives him trouble. Charlie is grateful for his friends.





Charlie forgets that he is no longer enrolled in Alice’s class at the Center for Retarded Adults and shows up for one of the meetings. When Alice sees Charlie has reverted entirely to his original state, she runs from the room weeping. Charlie senses that people feel sorry for him, and he decides to go live at the Warren Home. In his final note, he says that he is glad he got to be smart for a short time and that he got to learn about his family. He has a vague memory of himself as a genius: “he looks different and he walks different but I dont think its me because its like I see him from the window.” He writes goodbye to Alice and Dr. Strauss, and advises Professor Nemur that he will have more friends if he does not get so upset when people laugh at him. Finally, Charlie leaves a postscript requesting “please if you get a chanse put some flowrs on Algernons grave in the bak yard.”








What a great book it is!
Reply:He was a mentally retarded janitor who underwent an operation to increase his intelligence. The operation was a great success. He became more intelligent than the professors and doctors who gave him the operation. But then he faded back into retardation, and, like his lab rat friend Algernon, Charlie died.