How you view Failure could determine your Success....
I think that motivation, self-confidence, intelligence, and a whole range of other factors all play a part in the ultimate success of the entrepreneur. I would guess that some of these factors are related, also. For example, if somebody is self-confident (and therefore believes in their ability), they will probably be more motivated to try to achieve what they want. In some cases, someone lacking self-confidence may also lack motivation due to the belief they can't do something in particular.
Another factor I think is very important is how the entrepreneur view of failure. This isn't necessarily in business endeavours, but in general. I think there a really two main ways different people view failure, being:
Type A. Failure means they're not good at something.. It's bad.. They should try and forget the failure as soon as possible and get on with something else.
Type B. Failure's a normal part of life, and indicates an action they took was wrong. So they don't get upset over it, but analyse the situation, work out what's wrong, and become better at that particular task.
I think most people are either Type A or Type B, or somewhere inbetween depending on the circumstances.
To be a successful entrepeneur, I really think it helps to be a Type B person, because it really helps facilitate pushing forward and learning as you go.
Unfortunately, I think many people are really Type A people. Why is this? I'm not sure, but if I had to guess, it's probably a product of the school environment most people go through.
In my prior classroom experience, I tend to find that when teachers ask questions, students rarely raise their hands to answer unless they know they are right. There's a very big reluctance to answer and get things wrong, and I think many people come away from this experience "learning" that to fail is a bad, shameful, embarrassing thing.
When in reality, it's probably the best way to really learn something. :)