To be a great leader, you must be a great listener

Dream big by setting yourself seemingly impossible challenges. You then have to catch up with them.

The truth is this: the Earth cannot provide enough food and fresh water for 10 billion people, never mind homes, never mind roads, hospitals and schools.

I have always believed that there is no point in having regrets as you learn far more from mistakes than successes. Embrace a mistake and learn from it; don't regret them.

I have always been a huge believer in the inestimable value good mentoring can contribute to any nascent business

Look, if you can indulge in your passion, life will be far more interesting than if you're just working. You'll work harder at it, and you'll know more about it. But first you must go out and educate yourself on whatever it is that you've decided to do - know more about kite-surfing than anyone else. That's where the work comes in. But if you're doing things you're passionate about, that will come naturally.

And obviously, from our own personal point of view, the principal challenge is a personal challenge.