I can remember my mother sharing this story with me about my dad when he went to enlist.
My dad went to enlist during WW1. His name was Guy Allen. He didn't have a middle name. So when they were doing the paperwork, the man said, "You have to have a middle initial." My dad said out of disgust, "Well pee." So his name was written down on the inlistment paperwork as Guy P. Allen. He used that middle initial "P" for the rest of his life.

Harold Allen