in common was believing in themselves.
think about the very smart people you know. they may have great ideas, yet do not have enough self-confidence to take their concepts to that next level. also, give thought to those individuals who were far from rocket scientists but believed in themselves enough to create a million-dollar company out of a simple concept.
the difference between these two types of individuals is that those who were less confident convinced themselves that their idea would not be successful while the more confident people did not think twice about their ideas not working. in fact, what sold their concepts to others was first their belief in themselves 