When Audie Murphy applied to the Marines in 1942 at the tender age of 16, he was 5'5" and weighed 110 pounds. They laughed in his face. So he applied to the Air Force, and they also laughed in his face. Then he applied for the Army, and they figured they could always use another grunt to absorb gunfire, so they let him in. He wasn't particularly good at it, and they actually tried to get him transferred to be a cook after he passed out halfway through training. He insisted that he wanted to fight though, so they sent him into the maelstrom.