How can I become ultra-wealthy? No Joke.?

I want to be an industrialist. But most people are born into that sort of money and just grow it for fun. Other people are there at the right time with the right equipment. Like David Rockefeller (the first, not the abominable child he had that runs the trilateral commission) or Dale Carnegie or Bill Gates. I am willing to work hard. But I don't know what to do. I'd like to start a business. Maybe an insurance and liability business. But I have no idea where i'd start, and I don't want to go to business school. There's gotta be something I can do to get the ball rolling while still in college. Any serious suggestions? I keep thinking all the good I could do in the world with all that money.