The exploration of Jim's survival represents a strong notion of discovery.  From the character at the start of the novel to its end, there is a strong notion of self discovery in Jim's character.  He discovers more about his capacity for endurance and his ability to struggle and persevere in the face of wartime conditions and prison camps.   In some senses, Jim discovered some of the worst aspects of human beings, in seeing the treatment of prisoners in the camps and his own experience of being beaten and abused.  Additionally, Jim discovers that war is a horrific experience where there is no glory and valiant honor.  As a child, Jim's romanticized notions of war are dispelled by his experiences that reveal the cruel and agonizing conditions of war.  Being separated from his parents, Jim discovers what life is like on his own, cut from an immediate sense of family.  Finally, the ending of the novel reveals that Jim will never be able to fully capture the innocence of his youth for the spectre of being a prisoner and captive of war will always be haunting him, discovering a new aspect of his consciousness and state of being in the world.