For some reason, people take their cues from price action rather than from values. What doesn't work is when you start doing things that you don't understand or because they worked last week for somebody else. The dumbest reason in the world to buy a stock is because it's going up.
Observing that the market was FREQUENTLY efficient, EMT Adherents went on to conclude incorrectly that it was ALWAYS efficient. The difference between these propositions is night and day.
I think you should read everything you can. In my case, by the age of 10, I'd read every book in the Omaha public library about investing, some twice.
You need to fill your mind with various competing thoughts and decide which make sense.
At Berkshire, I both initiate and monitor every derivatives contract on our books ... If Berkshire ever gets in trouble, it will be my fault. It will not be because of the misjudgments made by a risk committee or chief risk officer.
If the world couldn't see your results, would you rather be thought of as the world's greatest investor but in reality have the world's worst record? Or be thought of as the world's worst investor when you were actually the best?
In some corner of the world they are probably still holding regular meetings of the Flat Earth Society. We derive no comfort because important people, vocal people, or great numbers of people agree with us. Nor do we derive comfort if they don't.