I saw a man walking on a sidewalk (Shanghai, 1989) while a woman was brushing it. He thought she had brushed dirt on his shoes so he just hauled off and punched her - without saying a thing. She then brushed some (more) dirt on his shoes. He punched her again. She brushed dirt on his shoes again. Etc - at least 5 times before my bus pulled away. They may still be there! After all, they both thought they were winning!