Like the soldiers who fought in World War II, most of the men and women who served in the U.S. military during the Vietnam War in the ’60s and ’70s were remarkably young, between the ages of 18 and 25. Those who volunteered to man the primary aircraft of the war, the helicopter, put their lives at a risk every day they were on tour. As a result, their commanding officers were often willing to look the other way when the pilots, gunners, and other crew members had their helmets painted in bright colors with their girlfriend’s name; their call sign or unit insignia; their favorite rock bands or comic-book characters; or mascots from their hometowns, in much the same way World War II pilots painted their leather A-2 flight jackets.