What did bromden learn about how to function in the middle of the fogging(real, not imaginary), by his experience I the military?

Bromden explains where the thick fog comes from. It emanates from the fog machines he saw during the war. The machines obscured the surroundings so that nobody could see anything in front of him. Bromden would get lost in the fog and always find himself returning to the same place. Bromden waits for Nurse Ratched to fog them in again; lately they have been doing it more and more now that McMurphy has fomented the rebellion of Cheswick and Harding to the point where they might actually stand up to the boys. Bromden compares the imaginary “fog machine” of the mental institution to the real fog that apparently surrounded him during wartime as a matter of military tactics. This tale indicates that Chief Bromden likely suffers from some sort of shell-shock caused by his war experience.