Doppleganger

I'm in the Strawberry having lunch when a regular fellow lunchtime "strawb" comes in and comes straight over to me; "Have you changed your shirt today?" he asks. I'm nonplussed. Is he commenting on my body odour? How sensitive his is smell? I hurriedly look for stains, rips and the like. "No, this is the only one (white) I've had on today" ... I wait expectantly.

"You've not had a blue shirt on today, no?"

"Definitely not", I tell him.

"Well I've just seen your ringer in Morpeth, this morning, in a blue shirt. I couldn't wait to get here to tell you I'd seen you but the white shirt completely threw me".