I find it quite useful to think of a (partly) free market economy as sort of the equivalent of an ecosystem. Just as animals flourish in niches, peop… - Charlie Munger

Richard Feynman as follows: “The first principle is that you must not fool yourself, and you’re the easiest person to fool.

forth. And the other is to evaluate the psychological factors that cause subconscious conclusions, many of which are wrong.

Obviously, you have to know accounting. It's the language of practical business life. It was a very useful thing to deliver to civilization. I've heard it came to civilization through Venice which of course was once the great commercial power in the Mediterranean. However, double-entry bookkeeping was a hell of an invention.
And it's not that hard to understand.
But you have to know enough about it to understand its limitations — because although accounting is the starting place, it's only a crude approximation. And it's not very hard to understand its limitations. For example, everyone can see that you have to more or less just guess at the useful life of a jet airplane or anything like that. Just because you express the depreciation rate in neat numbers doesn't make it anything you really know.