I think you actually start to admire and idolize Mr. Keating because he can do all the things that Todd can't do. Mr. Keating encourages behavior he never thought he would talk about. Then Todd begins to gain more confidence and stand up for himself. When Todd found out about Neil, I think that was his last straw. He was fed up with simply being an obstacle and not being able to stand up for what he believes in or what he wants to do. He's also tired of having to try to walk in his brother's shoes. His parents rub it in his face that his brother was a WONDERFUL person and that he could never be as great as him. I think he's just fed up with it and sees Mr. Keating as his only REAL relationship because he hasn't tried to push him into doing things. That's why he fell in love with Mr. Keating at the end of