The article was seriously editorialized. For example, while Warren Buffett tells newly minted rich people to invest in index funds, he tells aspiring investors to gamble on their brightest ideas (and not their seventh), since that's the one likely to make you rich. The article, of course, doesn't mention this.

There's a philosophy he goes by: stick within your area of expertise. It's done well for him, though it might not be quite so fun as trying your odds on the market.