Krebs was reading a book on the history of World War I and found it fascinating. The war ended in 1918. He returned home in 1919, so there were not many books about the war available as yet. A really good book on a war of such proportions would take years of research and interviews to complete.
He sat on the porch reading a book on the war. It was a history and he was reading about all the engagements he had been in. It was the most interesting reading he had ever done. He wished there were more maps. He looked forward with a good feeling to reading all the really good histories when they would come out with good detail mps. Now he was really learning about the war. He had been a good soldier. That made a difference.
Krebs had been involved in some of the most important battles of the war. He had fought at Belleau Wood, Soissons, the Champagne, St. Mihiel and in the Argonne. However, he was just a infantryman and, like most soldiers, did not really know much about what was actually going on. Now that he has a chance to read about the war, he is able to understand the strategies and objectives. It is rather ironic that he could not understand the battles he was involved in until he is back at home and reading about them in a book. He must feel glad that he is still alive to be able to read about the battles in which he could have been killed.
Krebs is recovering from the emotional traumas of war, but he seems to have enjoyed the experience. He reflects on
...all the times that had been able to make him feel cool and clear inside himself when he thought of them: the times so long back when he had done the one thing, the only thing for a man to do, easily and naturally, when he might have done something else.
These kinds of feelings were of great importance to Ernest Hemingway himself, and he is writing about himself when he writes about his character Krebs. Hemingway also wrote about the aftereffects of wartime experience in his twin stories "Big Two-Hearted River: Part I," and "Big Two-Hearted River: Part II." Characteristically, a lot of what is meant by these three stories is not explicitly stated (in accordance with Hemingway's famous "iceberg principle"), but is implied by the author and sensed by the reader. Krebs' disappointing experiences in trying to talk to the townspeople and to his parents about his feelings suggest that the protagonist, like Hemingway himself, felt that some things could only be understood by people who had personally experienced them.