When I was in my early 30s, I belonged to a small Rotary Club, which had two WWI vets in it, one just an enlisted man, the other a Major, who was a bit stuffy. The jabs of these two was entertaining.
My oldest uncle was an officer in WWI. He was a self-made millionaire in his 20s, left his business in the care of employees, volunteered, and was an Captain at The Marne, Meuse-Argonne, Chateau T, etc. He had lots of stories, and had a little den in his home for his friends to sit around. It had the rifle and sword of his ancestor from 1780, the gun belts and swords of ancestors from the Mexican War and the Civil War. He tried to enlist after Pearl Harbor, at age 54.
He was cotton broker, who supplied mills in England, so he had a lot of friends all over the UK, and felt like an attack on them was an attack on him. His respect for those who did not return was contagious.