Many intangible things are as important as they are difficult to discuss. An invisible ingredient in success. "You make your own luck".

PG in "Hardest Lessons" described some of it here:

"If you lack commitment, you'll just find that for some mysterious reason good things happen to your competitors but not to you. If you lack commitment, it will seem to you that you're unlucky."

I've had a hell of a time trying to convey this kind of stuff to other people. I've even doubted whether it's possible to convince someone who doesn't "get it". I love Andreesen's post myself, but I fear it's still to abstract to forward to the people I would like to convince.