You do not need to be a genius to be a successful investor, master the basics and the rest will fall into place:
"To invest successfully, you need not understand beta, efficient markets, modern portfolio theory, option pricing or emerging markets. You may, in fact, be better off knowing nothing of these. That, of course, is not the prevailing view at most business schools, whose finance curriculum tends to be dominated by such subjects. In our view, though, investment students need only two well-taught courses - How to Value a Business, and How to Think About Market Prices."
On the fine line between investment and speculation:
"The line separating investment and speculation, which is never bright and clear, becomes blurred still further when most market participants have recently enjoyed triumphs. Nothing sedates rationality like large doses of effortless money. After a heady experience of that kind, normally sensible people drift into behavior akin to that of Cinderella at the ball. They know that overstaying the festivities — that is, continuing to speculate in companies that have gigantic valuations relative to the cash they are likely to generate in the future — will eventually bring on pumpkins and mice. But they nevertheless hate to miss a single minute of what is one helluva party. Therefore, the giddy participants all plan to leave just seconds before midnight. There’s a problem, though: They are dancing in a room in which the clocks have no hands."
How to invest well:
“First we try to stick to businesses we believe we understand. That means they must be relatively simple and stable in character. If a business is complex or subject to constant change, we're not smart enough to predict future cash flows. Incidentally, that shortcoming doesn't bother us. What counts for most people in investing is not how much they know but rather how realistically they define what they don't know. An investor needs to do very few things right as long as he or she avoids big mistakes.Second, and equally important, we insist on a margin of safety in our purchase price. If we calculate the value of a common stock to be only slightly higher than its price, we're not interested in buying. We believe this margin-of-safety principle, so strongly emphasized by Ben Graham, to be the cornerstone of investment success.”
The difference between risk and volatility:
“The measurement of volatility: it’s nice, it’s mathematical and wrong. Volatility is not risk. Those who have written about risk don’t know how to measure risk. Past volatility does not measure risk. When farm prices crashed, [farm price] volatility went up, but a farm priced at $600 per acre that was formerly $2,000 per acre isn’t riskier because it’s more volatile. [Measures like] beta let people who teach finance use the math they’ve learned. That’s nonsense. Risk comes from not knowing what you’re doing. Dexter Shoes was a terrible mistake-I was wrong about the business, but not because shoe prices were volatile. If you understand the business you own, you’re not taking risk. Volatility is useful for people who want a career in teaching. I cannot recall a case where we lost a lot of money due to volatility. The whole concept of volatility as a measure of risk has developed in my lifetime and isn’t any use to us.”