Charlie Munger spent decades as Warren Buffett's right-hand man at Berkshire Hathaway, helping shape one of the most successful investment philosophies in history. But true to form, he never took credit for it.
Speaking at the Redlands Forum in California in 2020, an event sponsored by geographic information system software company Esri, the University of Redlands, and local nonprofit Town & Gown, Munger explained that his extraordinary financial success wasn't the product of genius. Instead, it came from a few basic mental frameworks he picked up almost by accident.
"What caused the financial success was not extreme ability," he said. "I have a good mind, but I'm way short of prodigy, and I've had results in life that are prodigious, and that came from tricks. I just learned a few basic tricks. There are all kinds of tricks that I just got into by accident in life."
Think Backwards to Move Forward
Munger's favorite approach was inversion. Rather than asking how to succeed, he asked what would guarantee failure, then made absolutely sure to avoid those paths. This wasn't abstract philosophy. He learned it doing real work with real consequences.
During his time as a weather forecaster in the U.S. Army Air Corps, Munger prepared reports that pilots depended on for their lives. His method for getting it right was characteristically unconventional.
"I said, 'How can I kill these pilots?' That's not the question that most people would ask," Munger explained. "But I want to know what's the easiest way to kill them would be so I could avoid it. There are only two ways I'm gonna kill a pilot, I'm gonna get him into icing his plane can't handle and that will kill him or I'm gonna get him someplace we gonna run out of gas before he can land. I just was fanatic about avoiding those two hazards."
Over, Under, and Kapow
Another mental trick came from artillery training. Munger learned how soldiers judged distance when firing mortar shells: aim a little over, then a little under, adjusting until the shell hit exactly where it needed to explode.
"Well, I never shot any damns shells but I've been using that mental trick all my life, that's how I determine what size to make something," Munger said. "Over and under and kapow."
It's a simple concept, but Munger applied it constantly. Whether sizing an investment, estimating value, or making business decisions, he used this bracketing approach to zero in on the right answer.
Good Enough Is Usually Good Enough
Munger also pushed back against the corporate obsession with exhaustive due diligence. Drawing on his experience as a lawyer, he argued that trying to achieve perfect certainty often reveals muddled thinking rather than thoroughness.
"You don't need perfect, if you're 96% sure, that's all you're entitled to in many cases," Munger said. "I see these people doing this due diligence and the weaker they are as thinkers, the more diligence they do."
The point wasn't to be reckless. It was about recognizing that in complex, real-world situations, waiting for 100% certainty means never making a decision. Strong thinkers can act decisively with less than perfect information because they understand the fundamentals clearly.
These weren't sophisticated investment formulas or proprietary strategies. They were practical mental habits Munger developed early in life and never stopped using. And somehow, those simple tricks helped build one of the greatest fortunes in American business history.
