This is a very interesting thread.
My late father served in the Royal Air Force from 1940 to 1946. He never talked much about his service years but after he died I discovered lots of memorabilia, bibles, cap badges, forage cap, buttons, dog tags etc. when I cleared his house. He left three photo albums covering the period from 1941 to 1943 when he served with the commonwealth pilots training scheme in Canada, lots of pictures of life on the base and of the aircraft as well as pictures of cities in Canada and USA which he visited while on leave. A head injury from an accident with an aircraft in 1943 led to him being in the hospital bay and shipped home and he ended his service with No.57 Maintainence Unit on the Solway Coast. I have carried on his memory by putting on a display of his artefacts and photos at Solway Aciation Museum where I am also a volunteer.
I also found that I had a great-great-great grandfather, John McKenzie, who served in the Lanarkshire militia around the time of the Napoleonic wars.