Jack
My grandfather's name was Jarvis. His mother was not a fan of the name AT ALL so she always called him Jack, and she was the only one. While still struggling to find the name for me very close to my arrival my parents stumbled upon a letter from my grandfather dated two days after Pearl Harbor, where he was stationed. The letter was to his mother some parts were blacked out because of the attack but you could see that he signed the letter "Your loving son Jack." and that is how I got my name.
-Tulsa, OK