7. "If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve."
Oh, and this one isn't bad, either.
15. "I think frugality drives innovation, just like other constraints do. One of the only ways to get out of a tight box is to invent your way out."