What's an unwritten rule everyone should follow? Here are some of the best answers we've seen . . .
1. Don't leave your shopping cart in the middle of the aisle. Move it to the side.
2. If someone hands you their phone to show you a picture, don't look at other photos.
3. Don't start drama at a funeral or a wedding. And don't PROPOSE at a wedding.
4. Don't heat up fish in the office kitchen, or anything else that smells.
5. Don't ask for something if the person only has one left. Like a piece of gum.
6. If you borrow someone's car, fill it with gas. Or at least get it back to where it was.
7. Don't end an apology with an excuse, or say things like, "I'm sorry YOU got upset."
8. It's okay to be wrong. So if you mess up, just admit it and say sorry.
9. If you cancel on a friend, it's your responsibility to reschedule.
10. Owning a plunger should be mandatory. (Also toilet-related: People who don't flush the toilet in public bathrooms should go to prison.)
(BuzzFeed)