Asking a stranger personal questions about their lives while making small talk in line at the grocery store is friendly in some places, but a major red flag in others. Greeting a new friend with multiple kisses on the cheek, not saying "hello" the second you enter a store, or leaving change on a bar in a country where waitstaff is salaried could earn you a place on the wall of shame.
While most touristy cities welcome travelers (and their wallets), respecting the codes of conduct and etiquette of the culture rather than behaving as if you never left your hometown is key to being a seasoned traveler. So, when a Reddit user asked, "What are some of the things normal in your country but weird or rude in other countries?" people were ready to share the mannersisms or behaviors that are standard where they're from, but major faux pas elsewhere.