My mam did the other day in Morrisons. It started unintentionally when she was told she'd pushed in the queue at the till. She asked where the end of the queue was and it was half way down the aisle with about 30 people waiting. She was going to go to the back but in conversation said to the young woman, "Oh my, is it Christmas already?" Meaning you only see queues like that at that time of year. However the young woman and others in the queue who had heard her gave her the 'poor dear she's confused look' and stepped back to let her in. So she paid for her two items and left the shop before anyone realises that she is totally compos mentis .