Do you have to have worked in a corporate to grow a big business?

Management Today recently published its list 35 Women Under 35 which profiles women to watch in the future.  If you look through the list and read the women entrepreneurs, nearly all of them have come from a corporate background.

This made me think - do you have to have worked in a corporate and experienced "big business" in order to  grow a business?  Many women I come across lack the confidence and self-belief that they can make it and maybe its because they don't have that corporate experience. What do you think?