Speaking of "that bloody wreck known as World War I," an excellent memoir that recollects the era is
Goodbye to All That, by Robert Graves. However, it suffers from a lack of fishing.

But Nick Lyons long ago recommended in the pages of
Cal Fly Fisher a slender volume entitled
Golden Days, by Romilly Fedden, who had served with the BEF on the Western Front. His is a memoir about fishing the Breton countryside prior to the start of the conflict. The war is mentioned, but only in passing, as Fedden was much more interested in depicting a world that he clearly loved, and that was quickly vanishing.