I think there is a moral lesson in this book about instant gratification. The book serves as a warning to readers about the dangers of instant and easy gratification. I feel that the best character that illustrates this warning is Montag's wife, Mildred. She has found meaning and happiness in life by seeking out the easiest and most mindless ways to achieve that happiness. She takes pills to help her mood, and she fills all of her time by watching television. Those lives that she watches on TV are more important to her than the reality that she lives in because her fictional world makes her happier than her real life.
"Happiness is important. Fun is everything. And yet I kept sitting there saying to myself, I'm not happy, I'm not happy."
"I am." Mildred's mouth beamed. "And proud of it."
She can't fathom why her husband would even consider anything that involves extra work in order to find happiness. The thought of reading a book and engaging that much mental horsepower to find pleasure boggles her mind.
This moral lesson about finding pleasure and happiness outside of a person's living room is echoed in Bradbury's short story "The Pedestrian" as well. In that story, the protagonist is arrested for going on a contemplative stroll around his neighborhood. Fahrenheit 451 supports that same idea. Bradbury wants his readers to continue to find happiness and meaning in slower and more contemplative activities. That's what Montag is searching for, and that's why Clarisse is so much more interesting to him than his own wife. She still exhibits wonder, curiosity, and independent thought.
I do not necessarily disagree with what the first answer says, but I think that it misses the biggest moral lesson of all in this book.
To me, the moral is that people must love learning and thinking and books or else those things will disappear. After all, it is not the government that comes up with the idea of censorship -- it is the people who demand it. This book tells us that it is up to people to protect their freedoms or the freedoms will be taken away -- not necessarily by the government, but possibly by their fellow citizens.
So Bradbury wants us to be more contemplative and less interested in excitement and easy pleasures.
1. Censorship is evil: it is an intrusion on freedom of speech, freedom of the press, and banning books is academic and moral neglect
2. Books must be protected at all costs: they cannot be changed, amended, rated with labels, stripped or watered down, or sampled. They must be preserved as a whole to protect the moral integrity of both art and artist.
3. A government that bans books is a fascist or totalitarian regime whose citizens must band together, rebel, and preserve knowledge and academic freedom.
4. Nuclear war threatens to destroy the planet. The only thing worse than a world without books is a world burned to ashes by nuclear warfare. In the 1950s, nuclear holocaust was a real threat to global annihilation.