My personal favorite from "Back Home" was Willie and Joe checking into a hotel as newly-minted civilians and recognizing the bellhop loaded down with our hero's bags as a former officer they'd served under with Joe remarking, "Why, Major Wilson! Back in uniform, I see."...
It goes well with one from "Up Front" where Joe (as a private) is saying to the Major, "One more crack like that, sir, an' you won't have yer job back after th' war!" ...
( A lot of Army officers were "minted" during the war because of the massive expansion of the Army and their commisions were temporary as Reservists and they wouldn't be allowed to retain the rank after the war, so they'd get out rather than serving as Corporals and Sergeants in peacetime. Also, many officers were employees of their now-subordinate former bosses from back home before the war.)