By the end of the book, Montag has completely rethought his life. He now understands that it is illogical and socially destructive to burn books. He has transformed from one who took pleasure in burning books to one who takes pleasure and a sense of responsibility in preserving books and knowledge.
After killing Beatty, Montag runs for his life. He hears a radio transmission from the police requesting everyone in the area to open their doors to look for Montag. Montag truly feels like a social outcast at this moment. Floating down the river, Montag has a realization that he is leaving a fake world and entering into a new, real world:
He felt as if he had left a stage behind and many actors. He felt as if he had left the great seance and all the murmuring ghosts. He was moving from an unreality that was frightening into a reality that was unreal because it was new.
He dreams of now living in a world where he has time to think. He has a fresh awareness of all the natural things around him. He even manages a half a smile. (Recall that in talking with Clarisse, she asked him if he was happy and he could not truthfully answer that question.) When Montag meets Granger and the other book specialists, he initially feels that he doesn't belong with them. This is because of his past. However, they embrace him. He becomes the Book of Ecclesiastes. He has made the transition from a destroyer of knowledge to a preserver.