Make no mistake about it, Warren Buffett is rich — $63.5 billion rich.

In fact, only 67 of the 200 countries listed by the United Nations have a GDP that is fuller than his wallet. With that said, he is also one of the hardest working people in business, and he has an incredible sharp mind with even "a vaguely autistic aura," according to his biographer.

What you may not know is that he is also an honest and pretty funny fellow.

I had the opportunity to hear him speak in 2002 at Georgetown University while pursuing my MBA. He was passing along advice to us soon-to-be (and wanna-be) business leaders, and while some of us had expectations of receiving sage investment advice, he laid out a few simple rules to live by.

He started by emphasizing that he was no different than anyone else in the world  and quipped that the only difference might be that we drive crappy cars and he flies around in a private jet.

He was quick, however, to point out that aside from winning, as he said, the "fallopian tube lottery" — being lucky enough to be born to loving and supporting parents — his success was not realized through luck or chance circumstance. We could all achieve his fortune if we worked hard, stuck with our core convictions, and applied common sense to our business lives.

And one more thing.

He emphasiz​ed the need to live righteously, because no bridge can be burned these days and dishonesty and cruelty will follow you for the rest of your business career. Instead, he suggested that by adopting and following one simple mantra in both your business and personal lives, all other parts of your life will fall into place:

"Never do anything in life if you would be ashamed of seeing it printed on the front page of your hometown newspaper for your friends and family to see."

It is that simple.

There was no top secret formula for valuing undervalued businesses. No stock tips. Just be good, do right, and treat others fair.