This was the only episode that could ever make me think of becoming a Sam girl. Evil Sam just rocks!
All he ever wanted was his brother. He couldn't have Sam, though. Dean was worthless.

Sam might not have remembered telling him that, but Dean made a point of reminding him. He also started favoring his left side. He wanted an apology, wanted to hear that he was worth something in his brother's eyes, and would keep pushing until he got it, no matter how painful it was for Sam. It was because if this that he knew he was selfish.