Since one of Death Be Not Proud's main themes is that defeating death means accepting its inevitability, Gunther forces the reader to accept the same thing. When Johnny gets better midway through his illness, our hopes are raised, yet we know that he will die and must adjust to it accordingly. Likewise, Gunther says he knew, from a doctor's face, that Johnny would die when he drove up to Deerfield to see him after the discovery of the tumor. Courage is the acknowledgment and acceptance of an ordeal, and Johnny does this throughout his illness, as the reader is forced to. Furthermore, Gunther maintains a dignified memoir by not sensationalizing Johnny's story. He puts the bald facts out on the table and demystifies death—it is something that happens, and we must get used to it. The revelation also contains a bit of an irony that deploys throughout the memoir. We may as well be reading an obituary when we learn of Johnny's death and of the facts of his life, but by the end of the book we feel we know him as a real person, and such a miniscule announcement of his death does him little justice.

Johnny's intellectual drive is remarkable, but sometimes he seems too concerned with it. He can be anti-social, locking himself away in his laboratory, but that is something all budding scientists must do. Worse, however, is his obsession with his academics; nearly all his letters boringly report on his academic achievements, and his focus infects Gunther as well, who continually boasts of his son's successes. It does not seem out of place that Gunther's last word on Johnny in the main narrative is a quote from Traeger that praises Johnny's unprecedented potential—one that applies to him as a human, but also as a success in life.

Johnny's other failings are more justified. He occasionally becomes hostile in the hospital, lashing out at his father ("subconsciously," Gunther believes) for his good health and resentful toward the doctors for keeping him cooped up. He also ignores the subject of death while talking with Gunther. Since he is able to discuss it with Frances, it seems that his reluctance to speak about it is only due to his company, but even then, it exhibits some fear on his side, and were he able to get over it perhaps Gunther would have had an easier time dealing with his son's death.

Gunther reports on many of Johnny's quips, both from when he was healthy and when he was sick—in fact, nearly all of his direct quotations have some wit in them. Most are comments on the absurdity of his situation, as when he claims he can keep time by his scheduled enemas. They all have a gentle quality to them, a way of reassuring others that he is all right, but they do seem to emanate from some kind of fear. Sigmund Freud argues that we create jokes out of anxiety—the greatest of all anxieties being death—and Johnny fits this theory. If the enemas were not so painful and humiliating, Johnny would not need to comment on them, but the sly, somewhat self-deprecating nature of his joke reduces their power; it is almost as if he controls them now, rather than what he implies in the joke. He even makes explicit references to his eventual death through humor, stating that his case will go down in history—meaning that he, soon, will be something historic, from the past. He also cracks wise about the expenses his illness brings, even ridiculing the inflated cost of an ambulance ride, and this is a tactic to reduce his guilt. Johnny's sense of humor brings out into the open issues that are otherwise difficult to discuss.