"I never took a day off in my twenties. Not one. And I'm still fanatical, but now I'm a little less fanatical."

"It's fine to celebrate success but it is more important to heed the lessons of failure."

"Your most unhappy customers are your greatest source of learning."

"We always overestimate the change that will occur in the next two years and underestimate the change that will occur in the next ten."