The conversation between Clarisse and Motag gets to the heart of the central theme in the book. In Montag’s society, no one questions anything. People live their lives as dictated by social convention. They don’t use their imagination; they watch television. Clarisse seems to wonder about this. Montag enjoys the conversation with her and her many questions, up to the point where she asks him about his work and he laughs. He says, "You are an odd one" and asks her if she doesn’t have any respect, but he is not really insulted until she asks him if he’s happy.
"Am I what?" he cried. But she was gone-running in the moonlight. Her front door shut gently. "Happy! Of all the nonsense." He stopped laughing. (part 1)This is the question that he takes with him, and wonders about as he returns home. He realizes that no, he is not happy. "She questions the rationale of the ideas that govern Montag's life and is the stimulus that makes Montag begin to doubt what he is doing." (enotes themes)