1. How to split complicated bills at a restaurant.
2. That new cars are bad investments. Also: Basic car maintenance.
3. The true cost of home ownership and mortgages. Also: How insurance works.
4. How to calculate compound interest.
5. That happiness takes work.
6. The real definition of consent.
7. How to give a compliment. Also: The art of conversation.
8. How to understand the concept of opportunity cost.
9. That hydration is life. Also: Basic cooking skills.
10. The art of haggling and negotiation. Also: How to spot a scam.
11. How to build your credit.
12. How to deal with the police. Also: What to do in an emergency.
13. Good time management.
- courtesy of a new list at Lifehacker.com