The list, according to Life. (annotated accordingly)

Because NCIS is one of the most brilliantly written and directed shows in crime drama history, I have came up with a few life rules of my own.

Gearhart's Rules:

1. If it feels wrong from the belt up, don't do it.
2. If it sounds wrong, ask three questions.
3. If it hurts, it works.
4. For every hour of work, relax 1/2 hour.
5. Wait for others to do unto you, then do it back.
6. Anything done alone can be done cheaper with more people.
7. Look, think, plan, reason, react.
8. If it looks wrong, you're not doing it right.
9. Never go anywhere without your knife (straight from Gibbs' rule)
10. Nothing you do will be the same twice.
11. Smart words and right hooks end negotiations.
12. Always know where you were.
13. Sportsmanship wears more padding.
14. Try less, struggle more. (Direct Warner Crocker quote)
15. Don't tolerate stupid.
16. Women and men persuade forwards, never backwards.
17. Check twice, do once. (adapted Til and Ricky quote from "measure twice, cut once")
18. Everything must make sense.
19. Nothing is coincidence (Another Gibbs' rule)
20. Look them in the eye, let them draw a lie up.
21. the world's only common denominator is "the great flood."