Perhaps you miss another point and the most important is BIG HARDWORK, most startup failed not because they don't have big idea or big capital but they don't work hard enough to conquer the obstacle in front of them. Big Idea might be something to start but you won't reached anywhere without work, Big capital will help you at first but the bigger the money you spent also the bigger the responsibilites to actually retrieve it back. Most people consider hardwork as something easier said than being done and thats why it mostly overlooked