The quality that best describes O'Brien is his capacity for introspection and reflective thought, leading directly to his use of memory in the novel. Of paramount importance to O'Brien the writer is his need to remember people and events from the past, to incorporate lessons learned (or not learned) into his present life. One way to understand how O'Brien becomes a writer is that writing is a way to manifest the past — writing is memory.
"O'Brien's" preoccupation with memory and re-memory derives in part from his inability to readjust to civilian life and forget his Vietnam experience. Though O'Brien attempts to make a case that his transition out of war was easy, he exhibits symptoms of post-traumatic stress disorder, including war-related depression, isolation, survival guilt, anxiety reactions, and nightmares. Writing is, in part, an attempt to quiet these things. Rather than forgetting his past, O'Brien confronts and re-confronts the various traumas of his life to resolve some of the elements of chaos he still feels thirty years later. He seeks not an end, but a resolution, and not through denial, but through memory.
A deeply affected and sensitive individual, the "O'Brien" character spends the novel searching for an emotional home, a feeling that he had as young boy in love and which he will never encounter again. O'Brien mourns the loss of innocence he felt growing up as a boy in the Midwest and feels a sense of betrayal from the community whose cherished, misguided, and uninformed beliefs sent him to war.
