When you don’t know who someone is, but instead of explaining it to you in a different way or giving you more relevant information, they just kept repeating their name.
“I saw John Murphy today”
“Oh, I’ve no idea who that is”
“You do John Murphy, JOHN Murphy”
“Oh, you do, John, the one with the face and the glasses”
“That’s not helpful”
“You know him you do. Anyway I saw him in town”