In Ray Bradbury's Fahrenheit 451, the question Clarisse asks Montag that seems so pivotal to his life is, "Are you happy?"
Montag is a fireman by trade. The job of firemen in this futuristic society is not to put out house fires, but to start them. Their overall purpose is to destroy homes that contain books, something is not allowed in this society. Other things have taken the place of books—things that anesthetize people toward anything of importance in the world. They do not ask questions or share opinions about anything, but happily ingest the propaganda pumped into their homes through their wall televisions and the seashells ear buds they listen to as they rest at night.
Clarisse and Montag meet on the street one day and begin to have conversations. She asks him about things he has never considered. She shares images of the world as it used to be. For instance, she speaks about dew on the grass in the morning. She holds a yellow flower under Montag's chin (a practice of young children) to see if he is in love: for if the flower reflects its yellow color onto the chin, the chin's owner is in love.
At first Montag thinks Clarisse is extremely odd. However, more and more in their brief association, Montag begins to consider the things she says to him. Life takes on new meaning for him. This galvanizes him forward to ask questions about who he is and what he does, planting the seed of desire for more knowledge—a seed that takes root and grows within him.
Perhaps the question that has the greatest impact on him is one that she throws over her shoulder as she says goodnight after their walk together:
Are you happy?
This concept is completely alien to him. He hears the question and he is incredulous—asking her departing back to repeat what she said. But she is gone. His immediate response is:
Happy! Of all the nonsense.
He stopped laughing. [...] Of course I'm happy. What does she think? I'm not?
Montag reflects on Clarisse, and how she was able to stir his mind to new ideas in the shortest bit of time.
What incredible power of identification the girl had...
He likens her to someone watching a marionette, anticipating what the puppet's next move will be. This is especially telling in that most of the members of Montag's society are nothing but puppets, marionettes. They are manipulated to think and act as society wishes.
As Montag ponders Clarisse's question, and then faces his wife's attempted suicide, along with emerging doubts he now has about things he had never before considered, he says...
I don't know anything anymore.
This is the beginning of a new life for Montag. It seemed that he was asleep for the longest time, but Clarisse quickly provides him with ideas, images and questions that change the way he sees himself and the world in which he was once so comfortable. It does not take long for him to realize that he is not happy, and with that knowledge he searches for something of value in himself, books and in society—or in the quiet rebellion surging beneath society's façade of satisfaction and personal fulfillment.