One, which I mention several times elsewhere, is the need for patience if big profits are to be made from investment. Put another way, it is often easier to tell what will happen to the price of a stock than how much time will elapse before it happens. The other is the inherently deceptive nature of the stock market. Doing what everybody else is doing at the moment, and therefore what you have an almost irresistible urge to do, is often the wrong thing to do at all.

Be extra careful when buying into companies and industries that are the current darlings of the financial community.

I remember my sense of shock some half-dozen years ago when I read a recommendation to sell shares of a company ... The recommendation was not based on any long-term fundamentals. Rather, it was that over the next six months the funds could be employed more profitably elsewhere.

History has shown that in every age and in every field of human knowledge, many of the views which almost everyone accepted as true and never bothered to think about further, were in time proven completely wrong.

My mistake was to project my skill beyond the limits of experience. I began investing outside the industries which I believe I thoroughly understood, in completely different spheres of activity; situations where I did not have comparable background knowledge.

Of one thing the investor can be certain: A large company's need to bring in a new chief executive from the outside is a damning sign of something basically wrong with the existing management - no matter how good the surface signs may have been as indicated by the most recent earnings statement.

Practical investors usually learn their problem is finding enough outstanding investments, rather than choosing among too many.