Acknowledge the complexity of the world and resist the impression that you easily understand it. People are too quick to accept conventional wisdom, because it sounds basically true and it tends to be reinforced by both their peers and opinion leaders, many of whome have never looked at whether the facts support the received wisdom. It's a basic fact of life that many things "everybody knows" turn out to be wrong.

My basic advise is don't lose money

Diversification is something that stock brokers came up with to protect themselves, so they wouldn't get sued for making bad investment choices for clients. Henry Ford never diversified, Bill Gates didn't diversify. The way to get rich is to put your eggs in one basket, but watch that basket very carefully. And make sure you have the right basket.

The first loss is the best loss.

If you were smart in 1807 you moved to London, if you were smart in 1907 you moved to New York City, and if you are smart in 2007 you move to Asia.

Tough times helped many commodities traders become lean and mean through consolidation, mergers and cost cutting. All that excess supply has been sopped up.

If everyone thinks one way, it is likely to be wrong. If you can figure out that it is wrong, you are likely to make a lot of money.