What are some fun, safe ways to break a social norm without breaking a law?

Some fun and safe ways to break a social norm without breaking the law could include the following ideas:
- Wear winter clothes on a hot day or wear a bathing suit on a cold day
- Talk to strangers on the elevator 
- Pick your nose while talking to someone
- Lick the plate at a restaurant
- Talk to someone in another stall in a public bathroom