I am seventeen and crazy.  That was about the first thing we heard from Clarisse, and in my opinion, was one of the most famous lines in the book.  She was the impact on Montag's goal, and in fact she was the purpose of Montag's goal.  She made him want to be different.  Her overall role in the novel was to be the rebellious teen.  She was most definately against the system.  She didn't believe in burning books.  She said that books were the knowledge we need.  If Clarisse could've changed anything in society, she would've made books legal and gotten rid of firemen.  My opinion of Clarisse is she is a smart girl.  I agree with her ways.