As a geek who's now trying to start my own company I can say that conversely, just being a geek who knows how to build things does not make success easy either; other skills matter too. I have gained a much greater appreciation for product management, UI / UX and sales. The hard thing to figure out is whether that guy with an idea who approaches you at a meetup has these other skills; it's a lot easier to B.S a track record.