I was walking through the back streets of West Palm Beach in Florida when I came across this girl, sat outside her house, advertising her mother's Yard Sale with a hand made sign. We spoke briefly but she was clearly in the zone and didn't really want me to distract her from her job if I wasn't there to buy. I took the hint, but figured I should let her know the sign was upside down before I got out of her way. "No it isn't, I just drew the arrow the wrong way." Incredible lateral thinking.