Originally Posted by Mickey_

Both.

In my opinion there are a certain set of essential characteristics that have to be present (willing to take risk, the ability to see 'the big picture' without getting lost in details, willing to sacrifice short term, ability to persuade, strong inner drive, dreaming big, believing in your own ideas, hard work, willingness to go against the grain, etc.) but from there on it's a constant journey of learning and honing your skills.

And yes, there are always exceptions - entrepreneurs that are nothing like what you've learned about/know (or think you know) about what it takes to be a successful entrepreneur.