Chaotic warfare
The memoir is shaped by Graves' experience of a chaotic battlefield. All war is inherently chaotic, because the tides of a battle could sway at any moment, but there is still a spectrum of chaos and order within an army's ranks. Graves reports that the battles he served in were absolutely riddle by chaos. The order that should have existed among the ranks quickly deteriorated, at least in part because the Germans had weapons that the British were not trained to face.
Expertise and authority
Although some people were experts in war leading into WWI, the truth of WWI is that the warfare looked so different because of technological progress that there is a dilemma in Graves' memoir about expertise. Before long, this dilemma turns into a full-blown farce; the military is promoting graduate students directly into roles of authority without proper military training. Graves finds out in real time that the military is sending him authority figures without training.
Malice and evil
During the wars, Graves sees malice and evil. He describes the use of chemical warfare as inherently inhumane, and he sees that on both sides, leaders use their soldiers in ways that he can't quite stomach. Then, after the war is over, he reports disturbing rumors of mistreatment among the British toward their German POWs. There is even a rumor that the government did not free all its POWs, but kept some for reasons unknown.
Paranoia, post-trauma, and mental health
Graves experiences a new kind of imagery that we would know today by the name "PTSD," but since there was no such diagnosis back then, Graves's experience is truly horrifying. Little by little, he realizes that the war has damaged his ability to attain mental health. He wonders if the flashbacks and paranoia will ever stop, and when he tries to get treatment, he finds that the psychiatric resources available to him are insufficient. His experience of PTSD leaves him with a struggle for hope.
