John Perry Barlow was a lyricist for the Grateful Dead. When he was 30 years old he wrote the Principles of Adult Behavior as a simple list of his rules to live by. I particularly love #25 - Endure, which speaks of resilience, grit, and determination.
1. Be patient. No matter what.
2. Don’t badmouth: Assign responsibility, never blame. Say nothing behind another’s back you’d be unwilling to say, in exactly the same tone and language, to his face.
3. Never assume the motives of others are, to them, less noble than yours are to you.
4. Expand your sense of the possible.
5. Don’t trouble yourself with matters you truly cannot change.
6. Expect no more of anyone than you yourself can deliver.
7. Tolerate ambiguity.
8. Laugh at yourself frequently.
9. Concern yourself with what is right rather than who is right.
10. Never forget that, no matter how certain, you might be wrong.
11. Give up blood sports.
12. Remember that your life belongs to others as well. Do not endanger it frivolously. And never endanger the life of another.
13. Never lie to anyone for any reason. (Lies of omission are sometimes exempt.)
14. Learn the needs of those around you and respect them.
15. Avoid the pursuit of happiness. Seek to define your mission and pursue that.
16. Reduce your use of the first personal pronoun.
17. Praise at least as often as you disparage.
18. Never let your errors pass without admission.
19. Become less suspicious of joy.
20. Understand humility.
22. Foster dignity.
23. Live memorably.
24. Love yourself.