People are unhappy for several reasons. First, they seem to be isolated from one another. As exemplified by Clarisse, she thinks her of her "family" as part of a television show. Her human contacts are also based around the show and the only things she seems to care about is having another TV screen on the wall. There is nothing of true value in her life. she has no family relationships, no children and does not think for herself. Thus, when she is unhappy, she has no real people to turn to and tries to commit suicide. Evidently, this is a common practice among people of their society. When Montag calls for help, all he gets is mechanical paramedics because suicide is such a common occurrence, the machines can easily be programmed to "fix" the problem. When she is "fixed", she returns to the same lifeless society where people's goals are to be happy and satisfied, not giving or fulfilled. This is a very shallow way to live. Lasting happiness usually depends on helping others, giving of yourself and working towards some goal---something the people in the novel try to avoid.