Montag is content with his life and doesn't recognize the problems in society or with his job. Even after meeting Clarisse, he remains ignorant. He's represented by a child who doesn't dare to leave the safety of his house.
Montag matures a bit, but he's still confused with his position in society. He becomes even more uncomfortable with society when the doctors come to "fix" Mildred after she attempts suicide. When a lady decides to burn with her books, he realizes he needs to change. Here Montag is a bit more matured, but still close to his house because he is unsure of where he stands.
Montag is shocked when he finds out Clarisse is dead. He's also feeling guilty because of his growing collection of books, and when Beatty visits his home and tells him he has 24 hours to return the books, he becomes distraught with his life, and tries to think of a way to escape his situation. He's at a bus stop because he is searching for a way out and is ready to leave.
Montag abandons his old life officially and goes to search for an old man he once met that he knows owns books and can help Montag. The two formulate a plan to take down the firemen using Montag. He's on a bus now because he has officially left his old life and is slowly becoming independent with the help of Faber.
Montag answers the fire call from his own house after he crosses the line and reads a book to Mildred and her friends. After he's forced to burn his house, he kills Beatty and runs, becoming a fugitive. He's sorrowful because Mildred was the one who turned him in. He's in the woods now because he's on his own now, running from everything he's ever known.
Montag successfully runs and finds other fugitives that call themselves book keepers who he'll live with from now on. He's extremely sad when his city blows up, because he's sure his wife is dead, and all the innocent people living in the city are too. He definitely at peace at the end of the book, because he realizes that with the help of the bookkeepers, he can truly change the world they live in.