The main takeaway was work as hard as you can (i.e. 80 - 100 hour weeks). Even if you're doing the same thing as the competition (assuming they work 40 hours), you'll still accomplish in 4 months what they would in a year. Hard work, tenacity, and a little luck is what separates the smart from the brilliant.
The people I've worked for that were putting in 12 hour days always seemed to be the people that wasted the most time at work.
Human's are biological creatures. Just like when we run, when you go for 30 seconds vs 3 minutes vs 3 hours vs 3 days, the relationship of what happens is not a simple linear one of input. We tire, we lose concentration, we actually get worse if we go all out for long periods than if we act in controlled and conscious burn with good amounts of rest and down time.
As another poster has said, what does happen is that the ones that put in the long hours, in my experience, are often the most incompetent, the magical thinkers, the ones most out of touch with how much they're doing, and the ones putting on the show. Of course, in this world, the ones that put on the show are the one's that often get the most rewards...
Musk is though, spot on with the first two points though. Things other people value. Tenacity.
Hard work, is of course needed, but baring some kind of ridiculous genetics which border on not existing, your productivity drops magnificently once you start going longer hours. That's primarily just for show...