When Bradbury wrote Fahrenheit 451, era of the McCarthy hearings was underway. Sen. McCarthy brought many people before the House Committee on Un-American Activities accusing them of being members or supporters of the Communist party. Often the people who were accused were artistic people (writers, directors, producers, actors, etc.) and often simply being accused was enough to end a person's career or severely limit it. It was a type of censorship and that is why many people associate Fahrenheit 451 with state censorship. "State" here referring to the United States in general.
The novel is not about state censorhisp so much as it is about the idiot masses. You could analyze how Bradbury criticizes the ignorance inherent in popular culture. The novel is a warning about how easily the masses can be entertained and duped into leading a meaningless existence.
Montag is blindly trudging through his life, living a very hollow existence. What real meaning does he have in his life? Mildred lives to watch her TV walls. She is overjoyed to be able to play a minor role in an interactive program, yet she could play a major role in her real life. However, she finds no meaning or relevance in her life with Montag, so she must live her life vicariously through the TV. The lack of meaning or purpose in her life is one reason she overdoses on the sleeping pills early in the novel.
Note too how the medics who arrive to save Mildred, inform Montag how busy they are with suicide attempts. Bradbury is making a statement about how people need books and ideas to develop meaning and purpose in their lives. The masses in Fahrenheit 451 are incapable of this; thus, the suicide rates are high.
Until Montag meets Clarisse, he is unaware of how pointless his life really is. Clarisse relishes the natural world and thinking and talking rather than simply being entertained. Once Clarisse helps Montag realize the power of ideas and the beauty of the natural world, he begins to change. Faber too is instrumental in this.