Carnegie and Buffett occur to me as counter-examples that you need to devote yourself to a specific field or technology.
It should be easy to see that one of the things that separates Warren Buffett from the rest of us is that he has a unique perspective of the financial world – he sees all of the dynamics and intricacies of the financial world in a way that few others do.
It took years for him to build the mental framework that led to his deep understanding and unique view of the world. And as a result of his devotion to this pursuit and his willingness to immerse himself in it, he developed the structural underpinning for the mental vista that yields the rare and valuable perspective that enables him to see the financial world with the clarity of a composer likely unattained by anyone in history.
This is why Goldman Sachs calls him when they need help, like they did in the financial crisis.
1) he buys equity in the private markets not in the public markets 2) he has capital to buy entire companies 3) he can evaluate a company based on the people, not based on financials 4) he commits to not meddling in operations. Today's tax structure forces entrepreneurs to sell because of huge tax implications of passing down a privately held company. 5) emotionally he is very strong and he is willing to wait on the sideline for years if necessary.
He holds on to huge amounts of cash. Meanwhile shareholders are getting mad that he is not getting the returns and start talking about how he should just pay out the dividends, people start talking about how he has lost his touch or his method is out of date. The market is skyrocketing. Then the crash happens and he buys tons of distressed assets at a discount and he is brilliant again.
And it doesn't hurt that he can get special deals that most people can't.
http://www.slate.com/articles/business/moneybox/2011/08/no_y...
On the Bank Of America deal.
This isn't an ordinary investment, in which an investor buys common stock. Buffett's $5 billion is buying him 50,000 shares of a special class of so-called "preferred stock," which will pay him a 6 percent dividend, or $300 million a year. Just for the sake of comparison, BofA's common shareholders get a quarterly dividend of one penny a share. That means that if you owned $5 billion of ordinary BofA common stock at its current price of about $8 a share, you'd be getting a paltry $25 million a year in dividends—less than one-tenth of what Buffett will get. (Earlier this year, BofA tried and failed to get permission from the Federal Reserve to increase the dividend.)
BofA can buy back Buffett's investment at any time for a 5 percent premium.
Challenging myself to find a photo of Warren posing ostentatiously with a car, I found this which cracked me up:
http://2il.org/wp-content/uploads/2014/07/warren-buffett-dri...
He's picking up a BIG MAC for chrissakes. His car is very ordinary-looking and not showy. It's a Caddy though mind you... he's not an animal.
Most of the photos feature cars. Is a car a sign of wealth? If Warren converted his entire net worth to Lamborghinis (say $200,000 each) he'd have about 400,000 of them. A Lamborghini is worth to him, proportionally, about what 25 cents is worth to me. Even if you're "only" Steve Ballmer that car is worth only 75 cents to you in rdiddly dollars. If you were hanging out with actual rich people flaunting your $200K car they'd be like yeah congratulations, you found a quarter, Janice would you call security and have this gentleman removed please?
EDIT: They'd be like oh yeah I bought four of those with the interest earned by my cat's litterbox. Janice would you etc.
Besides, they technically devoted themselves to the field of finance. They didn't just decide one day that they wanted to be billionaires and only work 1 hour per week.
They worked their asses off to get where they are today, and the goal wasn't even necessarily to make a fortune...