Independent reasoners are almost certain to make a splash given some talent and persistence, while those who start from what already exists face a ceiling on their impact.

ambition How much to take on and how hard to push: superlinear returns to effort, focus, slack time, and procrastination.

discipline Doing the work when you do not feel like it: whether showing up is the whole secret, or systems and enjoyment beat willpower.

innovation Where new things come from and how they spread: invention against diffusion, and being near the factory floor.