The Globe and Mail reports in its Friday edition that the ancient Greek temple that was home to the Oracle of Delphi had a maxim inscribed upon its entrance. The Globe's Tony Keller writes that in golden letters was written, "Know Thyself." Charlie Munger, the vice-chairman of Berkshire Hathaway who died this week just shy of 100, helped Warren Buffett turn that company into the greatest investment fund in history by relentlessly following and elaborating upon the wisdom of that famous precept. To be a successful investment manager, or a successful businessperson, you have to know accounting. Above all, Mr. Munger said, you have to know people. You have to accurately weigh the genius and folly, the potential and limits, of humans and their works. You have to see them -- and the companies they're running, the schemes they're pitching, the dreams they're dreaming -- in a true light. You have to see through both marketing moonshine and sincerely held beliefs. And the most important person you must understand is: you. The Buffet-Munger duo had a deeper pool of knowledge than probably anyone who has ever invested money, but they also accepted, and respected, the vast geography of their own ignorance and uncertainty.