My late, ex-FIL was called George, only his real name was Neil! I never worked that one out...
I went away to grad school and during a phone call home my brother was telling me about something George did, and a minute or so into the story I finally said, "Wait... who is George?" He said, "Dad. That's what he's called now." Then he carried on with the story. And from then on, he really was called George. I'm not sure my parent's neighbours knew his real name or that it wasn't George.