A margin of safety is achieved when securities are purchased at prices sufficiently below underlying value to allow for human error, bad luck, or extreme volatility in a complex, unpredictable and rapidly changing world.

A value strategy is of little use to the impatient investor since it usually takes time to pay off.

In a world in which most investors appear interested in figuring out how to make money every second and chase the idea du jour, there's also something validating about the message that it's okay to do nothing and wait for opportunities to present themselves or to pay off. That's lonely and contrary a lot of the time, but reminding yourself that that's what it takes is quite helpful.

The average person can’t really trust anybody. They can’t trust a broker, because the broker is interested in churning commissions. They can’t trust a mutual fund, because the mutual fund is interested in gathering a lot of assets and keeping them. And now it’s even worse because even the most sophisticated people have no idea what’s going on.

Successful investors must temper the arrogance of taking a stand with a large dose of humility, accepting that despite their efforts and care, they may in fact be wrong.

Be focused on process and not outcome

Right at the core, the mainstream has it backwards. Warren Buffett often quips that the first rule of investing is to not lose money, and the second rule is to not forget the first rule. Yet few investors approach the world with such a strict standard of risk avoidance.