When Johnny was six, he stated that God was "what's good in me," and his drive to do good stays with him through his short life. What makes this inherent goodness more exceptional is his abundance of other supreme qualities. He is exceptionally intelligent, devoting himself to the sciences with both his mind and heart; his wit is pointed yet gentle; and he is mature beyond his years. He combines the best of childhood and adulthood—a child's endless curiosity about the world and an adult's maturity in understanding what to do with that curiosity. But two other qualities shine through in Johnny, and they often connect: his selflessness and his courage.

Johnny is certainly selfless in the conventional way, as a considerate, polite young man. But it extends to his attitude toward pain. He never lets anyone else pity him, not out of pride, but to spare their feelings; when he first discovers he has a tumor, he wonders how to break the news to his parents. There are only a few instances in the memoir when he reveals a deeper hurt, and even these are likely tamed versions of what he is really feeling. Gunther believes that Johnny leaves his diary out on occasion so that he, indirectly, can communicate to him and Frances about matters he'd rather not discuss, but his entries, too, never descend into self-pity.

It is unclear at times whether Johnny's stoicism is the result of his selfless attitude or of his everlasting courage. While his parents continually hold out hope that a miracle cure will be discovered, Johnny rarely puts stock into the next big therapy; a part of him seems to know throughout his illness that he will die soon, which is why he twice says, "But I have so much to do, and so little time!" Courage is not attained by ignoring death—although Johnny does seem to do this from time to time, as when he turns away from poetry on death while reading with his father—but by accepting it with dignity, and this is the way to defeat, not defy, death. His resistance is to go on living and doing as much good in the world as long as possible, not to overlook his fate. Of all his qualities, his courage and selflessness inspire others most, and Death Be Not Proud can be read not only as a story of how to defeat death, but how to live a life.