"Change the world" is only part of the equation. But what drives the hacker entrepreneur day to day? It's the adrenaline and focus supplied by the promised emotional payoff of a completed mission. Any veteran of a website launch knows what I'm talking about. This is why we're entrepreneurs, and it's the subject of this humorous video.
http://www.youtube.com/watch?v=RgNyoxpENXc
And no, it doesn't ask you to shell out any $$.