Commitment is not letting people down. That's very important in life.

You can't run a business without taking risks. The brave may not live forever - but the cautious do not live at all!

I never went into business to make money, but I have found that if I have fun, the money will come.

We will eventually build space science labs and hotels, prodding the capability for missions beyond the orbit of the Earth. Our space-hotel guests will be able to take breath-taking excursions, flying a couple of hundred feet above the Moon's surface in small two-man spaceships. In time, we will launch missions to Mars and beyond.

All successful people - not just entrepreneurs - have got things wrong over and over again before finding the right solution.

About 40 percent of my time is spent on social issues and building new organizations, more for the benefit of the climate or health issues.

A little humour is good for the soul - regardless of how old you may be.