Fahrenheit 451 part II

Another part of Fahrenheit 451 that annoyed me was at the beginning of the book, Guy was a devoted fireman who did not question his job. However after one talk with Clarisse, he changes his entire way of thinking. He begins to question his job, his wife and the way the world runs just from the observations of a teenager. Guy ends up killing Beatty which he would have never done before his chats with Clarisse. To me it just seems very improbable that a grown man would totally change his life around after only a few talks with a teenage girl.