Lots of terrific war poetry, some of it by gay men. That's what else I know.

World War I was my grandparents' war (one of my grand-uncles was a soldier in the war), so I grew up thinking of WWI as much closer than it is now. I didn't learn much about it in school, but quite a few of the mid-twentieth-century memoirs that I read as a teen had WWI in the background. For me, that period was when "history" started to fade into "contemporary."