1. Never EVER ask someone when they're due, unless you are absolutely positively sure they're pregnant.
2. Living above your means and/or trying to keep up with the Joneses will eventually lead to disaster.
3. Drinking to overcome social anxiety is another recipe for disaster.
4. If someone talks about other people to you, you can be damn sure they'll gossip about you.
5. Nobody likes a bragger, but if you meet one, try to understand that they're probably insecure, so give them some attention. (Consider it your good deed for the day.)
More to come...