My father was in World War I in the Army. He fought in France and the Argonne Forest.
He always said the toughest thing for him was watching the "younger" men get killed in the trenches and getting gassed with mustard gas. On one occasion he gave his gas mask to a noncom who didn't have one, peed on his handkerchief for a mask, got sick and laid in a wet trench for two days trying to recover. And the "best" time was relief of duty to go to Paris. He woke up one morning with a blonde on one side and a brunette on the other and had no idea how they got there!
He was a first lieutenant but got a "battlefield commission" with promotion to captain commanding a company, but it was never recorded. He came home to Winchester, Ill. Became an optometrist in Kansas City, practiced in Joplin, Mo., then went back to Kirksville, Mo., and became a DO with specialty in eye, ears, nose and throat. He practiced for 60 years and retired to a small family cabin on Grand Lake in Oklahoma and his home in Joplin. He died a blessed man with three kids and families fairly close. Mom left him in 1965.