Book by Charles T. Munger published in 2006
This is likely the most important book I've read to date. Ultimately, this is a book about how one of the most successful investors in history has structured his way of thinking. His approach of adopting the best mental models from all disciplines applies to anyone.
Charlie is simply brilliant, and this book is a fantastic summary of his views. What he preaches is to understand the big ideas in all the big disciplines, instead of becoming yet another "man with a hammer". The book is filled with references to the most important mental models in a dozen disciplines, and I've spent hours and hours deep in Wikipedia rabbit holes from interesting sources and references. This is why it took me months to go through.
As Charlie says, "In my whole life, I have known no wise people (over a broad subject matter area) who didn't read all the time -- none, zero." It's absolutely incredible how much knowledge he's been able to accumulate in his lifetime. It's filled with analogies from Captain Cook to Planck, and touches on subjects from psychology, to biology, to aviation, to economics, to mental models from engineering. It's clear that Munger understood biases and how we tend to fool ourselves long before Thinking Fast and Slow was released. He goes over memorized checklists to understand psychological effects and how they compound on each other. Munger practises some of the strongest morals I've seen since Franklin.
This book taught me to consider the second-order and third-order effects just as much as the first-order. Munger and Buffet essentially sit around for months, reading and reading hours and hours a day. Once in a while, they'll find something and invest in it. Their approach to investing is interesting, because they understand that each decision takes a lot of work to get right. Therefore, they choose to spend a lot of time making each decision with patience, and let the outcomes of those decisions compound. People who make good decisions do exactly that. They engage early and spend a lot of time gathering information and evaluating, instead of implementing. The winner is the person who makes the fewest, calibrated bets. "Decision makers gravitate towards ideas that seem risk free and reject these with modest risk and high potential trade-off." It's the person who understands when they're outside their circle of competence and either widens it, or delegates.
"Spend each day trying to be a little wiser [..] most people [..] then get what they deserve."
Note: You can't buy this book on Amazon. You'll have to order it through this website. It's big and costly, but it's well worth it.