I'll tell you about my grandfather, Edward, who was born the 8th of February 1901, and he signed up for World War I on the 4th of December 1915. He was also in World War II, but I don't have any dates as to when he joined.
He was also signed up in World War I with the Canadian Overseas Expeditionary Force, and he was part of the Winnipeg Light Infantry, the 222nd Battalion, and he was transferred to the 100th Battalion on the 5th of September 1916.
He sustained injuries, but I think that was in the Second World War. I don't have too much history of his time in the Second World War, but apparently he did lose a lung.