This fact should have immunized me against the potential for, or at least possibility of extreme stupidity. But it still astonished me when I run into someone incredibly obtuse in my day to day life.
Recently I was in a cafe with my Smaller Half. We ordered some coffee and, because we wanted something to eat but didn't want to spend too much, we also ordered some fruit toast. The girl behind the counter looked at us in disgust and contempt, as if we'd asked for a mug of warm vomit, and asked us what we meant. Admittedly, my Smaller Half is not of Anglo descent, so she doesn't really have the right to just waltz into a shop and order stuff using our language, so a brief period of confusion is understandable.
My Smaller Half repeated her request for fruit toast, politely at first, then in sentences increasingly bereft of such ornaments as courtesy, subordinate clauses, or verbs. Finally she was reduced to tapping her finger on the glass case where the (as yet untoasted) fruit toast was displayed, saying "Fruit toast?" in the same tone of voice that explorers used in 1950's action serials when talking to the natives - "You likey? You likey shiny beads?" and the poor shop girl was using her tongs to prod the muffins, the custard tarts, the dead blowflies, anything and everything EXCEPT the fruit toast in a desperate attempt to decipher what we were asking for.
Finally something registered in the shop girl's tiny brain and she gestured at the fruit toast - "That? That's raisin toast."