Themes are the fundamental and often universal ideas explored in a literary work.

Courage and Willpower in the Face of Death

In Death Be Not Proud, Johnny faces an overwhelming adversary for anyone, let alone a teenager: death. The poem by John Donne that opens the memoir (Divine Meditation 10) is an attack on death, and, to an extent, Johnny and his family do attack his tumor—through operations, diets, injections, and so on. But more than that, Johnny seems to reach a placid acceptance of death while he fights it. He never tries to defy death, but, rather, he simply loves life too much to let it go. He twice exclaims, "But I have so much to do, and so little time," and the statement indicates not a fear of death but a desire to live. Johnny even says at one point, in what seems to contradict his optimistic outlook, that the "worst thing is to worry too little" about death. The implication is that one must not agonize over these questions of death but accept them as a battle. And, for Johnny, a battle it is: he endures surgery after surgery, physical debilitation, constant moves in and out of hospitals, and the loss of a normal adolescence, yet he rarely complains. When he does, it only shows the strength of his conviction to get well. Mostly, he keeps his fears to himself, not out of pride, but to spare others. Everyone who comes to know Johnny finds him remarkably courageous and mature about his fate, one that he rarely acknowledges but seems to be aware of deep down. Johnny, however, focuses on living his life—furiously keeping up with his lost schoolwork, crafting interesting science experiments, and maintaining contact with friends. While it may simply be good fortune that his life extended far past what the malignancy of his tumor normally would have permitted, one cannot read Death Be Not Proud and not feel that Johnny's unwavering bravery may have had something to do with it.

The Uniqueness of Loving Life

Gunther often meditates on how all the traits that we know of a person emanate from the brain; it not only controls thought, but everything from a person's gait to his smile. He cannot explain away the irony that a tumor happened to inflict itself upon Johnny's most refined part of his body, but the best the tumor can do to destroy the teenager's mental capacity is occasional amnesia attacks. Johnny constantly rises above his illness and puts his brain to use in all areas of life, both intellectual and interpersonal. He possesses a remarkable intelligence, especially in the fields of chemistry and physics, and hr makes an intriguing experimental discovery about ammonia as well as demonstrating an awareness beyond his years of a difficult physics problem. His wit, too, is sharp and perceptive, though sometimes self-deprecating. This would all account for little were he not able to transmit his intelligence into a deeper maturity, affability, and selflessness, which impresses all whom he meets. Many people can have a memorable intellect, but few can combine that with something that transcends mere personality—a genuine humanity. As early as age six, Johnny decided that God was "what's good in me," and his drive to do good, in science and in life, becomes his philosophy, one that surprisingly few people ever embrace, let alone children. Frances remarks that Johnny's sum of passions, his "love of love" and "love of life," is what she has learned from him and hopes will pass on to others. Their hundreds of condolence letters surely testify to his success. His unremitting courage is better understood when we see for how much he had to live, on both abstract and personal levels.

Childhood versus Adulthood

Johnny lives more than a crucial year of his adolescent development while facing an illness that most people assume will soon kill him. He is described physically by his father as somewhere between child and man, and this portrait also applies to his personality in the best terms. The child in him is curious for knowledge without wanting to hoard it, and the adult in him is able to utilize it elegantly and maturely—Gunther even remarks once that Johnny's intellectual development has become frightening. He loves people and things for their own sake and unconditionally, as children are wont to do, but he has a deep understanding of what love means and how to express it. Overall, he has a child's innocent passion for life and an adult's sensitive maturity for how to approach the inevitable pitfalls along the way. These attributes show up in less obvious combinations too. He is polite to all who care for him, yet he also manipulates the doctors to elicit the information about his illness that they try to shield from him. He is curious about his illness, but he is often unaware of the purpose of simple procedures he undergoes. Johnny's rapid emotional maturation presents another difficulty: how much freedom should Gunther and Frances grant their ailing and aging son? He is, after all, already thinking about girls and the senior prom. The tension between extending his life—restricting Johnny to rest—and enhancing what he has left of it—allowing him the independence a seventeen-year-old wants—appears in the later stages of the memoir.