The fireman Montag meets seventeen-year-old Clarisse McClellan just a few pages into the famous science fiction novel Fahrenheit 451 by Ray Bradbury. He has just finished a book-burning session, left the fire station, and taken the subway to his neighborhood. While walking home along the moonlit sidewalk, he meets Clarisse. She recognizes his occupation from his uniform and the smell of kerosene that lingers on him. He immediately senses that she is highly observant and that she is checking him out. Bradbury writes,
He felt she was walking in a circle about him, turning him end for end, shaking him quietly, and emptying his pockets, without once moving herself.
They walk together, and Clarisse confesses that she is "crazy." She justifies this utterance by saying that she is seventeen, but what she really means is that she is an anomaly, because she likes to be outside walking, smelling things, looking at things, and watching the sun rise. She doesn't enjoy the popular forms of entertainment, such as the video presentations on the parlor walls, but she likes to watch people. We understand from her comments about firemen having once put out fires and drivers not slowing down to really see things that she is intensely observant.
Clarisse is probably able to discern small clues in Montag's behavior that give her hints that he is probably not as happy as he lets on. Additionally, though, we perceive that Montag converses with Clarisse without judgment and asks her questions for clarification. Most people in the society that Bradbury subsequently describes would not listen to her at all. Montag's attitude as he listens as well as nonverbal clues that Clarisse picks up help her perceive that Montag is more unhappy than he appears. Her perceptions are right, of course, because as soon as Montag enters his own home, Bradbury refers indirectly to the books that Montag has hidden behind the ventilator grille in his own home.