Never forget that Jerry Falliwell was also a “doctor”, as painful as that is to say. So, you ate in the Subway at the front of the store? Guy must have fell on hard times, I guess.
I've read, more than once....so there may be a hint of truth in it, that it came from slavery and the early days of manumission...blacks weren't allowed to have last names, so they started choosing unique names. Kind of a "If you're only allowed to have one name, make the most of it" deal.
I had an uncle named Shirley, it's an old southern name. He was also 6'6" and one mean son of a bitch. No one called him Shirley.