The Doctor & Lorna Dane
It was the same question again, but at least this time it was asked a bit differently. "I'm called the Doctor because it's my name. Why are you called Lorna?" He returned with the smile still in place, if a little amused this time.
He'd consulted the list of possible questions, but they were all a bit too boring for his tastes. He found more out about people by spending time with them, and watching how they reacted to things. "Are you having a nice time, tonight?"