Rather, risk is a perception in each investor's mind that results from analysis of the probability and amount of potential loss from an investment. If an exploratory oil well proves to be a dry hole, it is called risky. If a bond defaults or a stock plunges in price, they are called risky. But if the well is a gusher, the bond matures on schedule, and the stock rallies strongly, can we say they weren't risky when the investment after it is concluded than was known when it was made.

Pressure to produce over the short term - a gun to the head of everyone - encourages excessive risk taking which manifests itself in several ways - fully invested posture at all times, the use of leverage, and a market centric orientation that makes it difficult to stand apart from the crowd and take a long term perspective.

Always remembering that we might be wrong, we must contemplate alternatives, concoct hedges, and search vigilantly for validation of our assessments. We always sell when a security's price begins to reflect full value, because we are never sure that our thesis will be precisely correct.

Warren Buffett once wrote that value investing is like an inoculation--it either takes or it doesn't--and when you explain to somebody what it is and how it works and why it works and show them the returns, either they get it or they don't.

Benjamin Graham wrote, "Those with enterprise haven't the money, and those with money haven't the enterprise, to buy stocks when they are cheap."

To achieve long-term success over many financial market and economic cycles, observing a few rules is not enough. Too many things change too quickly in the investment world for that approach to succeed. It is necessary instead to understand the rationale behind the rules in order to appreciate why they work when they do and don't when they don't.

Investing is the intersection of economics and psychology.