Paul Graham's "How to Do Great Work" is excellent.
40 of my favorite ideas from the essay:
1. Curiosity is the best guide.
2. Being prolific is underrated.
3. If you asked an oracle the secret to doing great work and the oracle... See more
If you have one truly good idea in your life, that is more than enough.
To improve your mind, read fiction. We spend the vast majority of our professional lives in pure knowledge-gathering mode; there are different, deeper truths hidden in stories.
“Never quit” is terrible advice. Try lots of things, quit lots of things. Your time is not infinite.