What three thing's did Eddie learn during the war?

In these chapters, Eddie learns that what he accepted as truth during his earthly life actually contains a bit of fiction. He has long blamed a faceless enemy for shooting him in the knee, but in Heaven, Eddie learns that his own Captain shot him to prevent him from entering the burning tent.

Eddie learns that the Captain had to make a choice for Eddie - either he could let him die or he could salvage his life, even though he knew Eddie would be wounded forever.

Eddie learns that nothing good came from the war.