Why Didn't I Die: A Memoir of PTSD - Hardcoverby F. W. Kirkpatrick (Author) Fred Kirkpatrick served with the famed First Infantry's Black Lions, as a combat infantryman in Vietnam 1967. He was exposed to Agent Orange and struggled to try and understand what PTSD was doing to his life and writes about those struggles as a new author in his memoir of PTSD, "Why Didn't I Die." In a strange twist of irony, his father, nearly fifty years earlier, was exposed to Lethal Gas in World War I as a combat