Why does O’Brien use repitition in the chapter 12, the man I killed?

Tim has no way of knowing anything about the young man he killed, and yet he makes up an entire, detailed life for him. The repetition seems a coping mechanism. This becomes, for the reader, the truth of the man's life. Though it may not be actual fact, it is the truth, because it feels true. Also, it is what Tim needs to process that he has taken a life; while most people would work to de-personalize the body, he works to give the body humanity in order to ground himself in reality.