It just seems logical that sticking to investing in only a small number of companies that you understand well, rather than moving down the list to your thirtieth or fiftieth favorite pick, would create a much greater potential to earn above-average investment returns.

There’s a virtuous cycle when people have to defend challenges to their ideas. Any gaps in thinking or analysis become clear pretty quickly when smart people ask good, logical questions. You can’t be a good value investor without being an independent thinker – you’re seeing valuations that the market is not appreciating. But it’s critical that you understand why the market isn’t seeing the value you do. The back and forth that goes on in the investment process helps you get at that.

Figure out what something is worth and pay a lot less.

Something out of the ordinary course of business is taking place that creates an investment opportunity. The list of corporate events that can result in big profits for you runs the gamut—spinoffs, mergers, restructurings, rights offerings, bankruptcies, liquidations, asset sales, distributions.

Value investing doesn't always work. The market doesn't always agree with you. Over time, value is roughly the way the market prices stocks, but over the short term, which sometimes can be as long as two or three years, there are periods when it doesn't work. And that is a very good thing. The fact that our value approach doesn't work over periods of time is precisely the reason why it continues to work over the long term.

There's a clarity that comes with great ideas: You can [easily and simply] explain why something's a great business, how and why it's cheap, why it's cheap for temporary reasons and how, on a normal basis, it should be trading at a much higher level. You're never sitting there on the 40th page of your spreadsheet, as Buffett would say, agonizing over whether you should buy or not.

Choosing individual stocks without any idea of what you're looking for is like running through a dynamite factory with a burning match. You may live, but you're still an idiot.