Perhaps the primary theme in The Fault in Our Stars is the transient nature of life itself. From the beginning of the story, the reader is aware that the narrator, Hazel Grace Lancaster, is suffering from cancer that will eventually kill her. Hazel knows that her life will be brief, and this defines how she approaches it. She chooses not to waste her time on what others believe to be “cool.” She wants to do things that will make her happy. However, at the same time, she spends an enormous amount of her time thinking about a single book, An Imperial Affliction, rather than seeking out another favorite—perhaps for the comfort of knowing that she is already familiar with this story, despite its frustrating lack of resolution. At the same time, her terror of hurting others by dying means that she creates layers of isolation around herself.

This situation only changes for Hazel when she falls in love with Augustus, a boy whose approach to life is entirely different. Tellingly, however, it is really when Augustus goes into decline, eventually dying, that Hazel truly recognizes a fuller meaning of even a transient life. She finds that she is “happy” to have known and loved Augustus, even if only for a short time, because this is what life is for them. When she met Augustus, neither of them thought that he would be the one to die, but their brief relationship—driven by Augustus’s determination to seize the day and take what he could from life—leaves Hazel a wiser, happier, and more open person. She is no longer too terrified of her own mortality to be close to people.

Both of the main characters in The Fault in Our Stars have supportive families, but in both cases, these families often struggle to interact with their children. Hazel feels that her mother is often driving her to do things she would rather not do, such as attend celebrations and do things other girls of her age might enjoy. She recognizes that this is because her mother loves her and wants her to be happy, but at the same time, she fears that Mrs. Lancaster’s life revolves entirely around her daughter and her cancer—and that this form of love will leave her unable to cope in a world without Hazel.

At the same time, Augustus’s family draws comfort from a religion which no longer really resonates with their son. They rely upon a support system that helps them but does not really bring them closer to their child.

The difficulty for these families is that they cannot possibly understand what their children are going through. For this reason, the children of the cancer support group also rely heavily upon a “found family” of their own design. When Isaac’s girlfriend, Monica, who is a healthy teenager, breaks up with him, it is Augustus and Hazel who comfort him, accepting and encouraging his right to be angry with the world. And when Augustus arranges a “prefuneral” for himself, it is Hazel and Isaac who give the eulogies, a task that would normally fall to a family member. Hazel is pleased when Augustus completes the circle by writing an obituary for her, too.

Although the teenagers in the story certainly love and are loved by their families, in a situation as isolating as theirs, they also need their secondary chosen family in order to feel completely understood.

Many coming-of-age novels involve a first (or early) relationship that is definitive for the protagonist. The protagonist will firmly believe that they...