17 American Behaviors Considered Rude in Other Countries

13.Going Sans-mask While Sick 

If you live in a major metropolitan area, there’s a good chance you’ve seen a Japanese person sporting a surgical mask, even if they’re, say, wearing business attire and probably not fresh out of surgery. In the United States, a lot of people see this as a bit silly, but you should thank those mask-wearers—it’s generally a common courtesy for people who feel like they’re coming down with something and don’t want to spread their germs. It makes sense, considering Japan is one the most densely-populated and urban large countries on earth.