1. Whether or not to have kids.
2. Getting married.
3. A big move to a new home.
4. Learning to drive.
5. When to retire.
6. Buying property with your significant other.
7. Deciding to break-up when you're in a serious relationship.
8. Figuring out how to save or spend your money.
9. Getting a divorce.
10. Quitting a job.