There's this expectation that there's "something different" that separates successful startup founders from "common folk". And it just doesn't exist. I think the barrier of intimidation is one of the biggest things most people aren't fortunate enough to experience.
Like I said, I know more than a few YC folks, I've interviewed (and was rejected) once from YC, and every person I've met struck me as utterly normal in most ways. They merely possessed a bit more experience and in general know a tad more than the average person.
There's no reason you can't do a startup right this instant. Do not let YC's rejection/acceptance dictate your path.