Imposter Syndrome is rampant in the startup world, even when people don't seek out the hype. We love to elevate people to rockstar status, even if they don't want it. In my own, modestly-successful life, my attempts to explain how little influence I have are generally taken as humblebrag attempts, rather than as an honest attempt to communicate.
If it's easy for people who don't seek the spotlight to have it turned upon them, it's far worse for those who do seek it.
The good news is that you can bask in the spotlight without ever creating a billion-dollar company or changing the world--we're willing to give you rockstar status on potential, rather than achievement.
The bad news is that achieving enough to justify rockstar status is damned hard, and it's a lot harder to be a has-been than a never-was. As Harvey Dent said in "The Dark Knight," you either die a hero or live long enough to become the villain. Jerry Yang can testify to the truth of that statement, and he actually created a billion-dollar company that employed tens of thousands of people.
Anyone will become insecure if they receive accolades they don't believe they deserve, but desperately want to retain. To eliminate that insecurity, don't pretend to be something you're not.
If you don't erect a facade, you won't have to waste your energy defending it. If you've accomplished great things, there's no need to worry about tooting your own horn. If you haven't accomplished great things, you should focus your energy on doing something remarkable, rather than trying to prop up an inherently unstable and unsustainable reputation.