Man is not sum of what he has already, but rather the sum of what he does not yet have, of what he could have.

A great obstacle to happiness is to expect too much happiness

Your ability to maintain a positive attitude in the face of challenges is a powerful asset for achieving success.

What others think of me is none of my business.

Logic will get you from A to B. Imagination will take you everywhere.

I don't know who my grandfather was, but I'm much more concerned to know who his grandson will be.

Do not turn back when you are just at the goal.