Over the summer, I came across several posts that talked about a mental model known as The Inversion principal. It’s based on a simple tenet from the German mathematician Carl Jacobi — ‘invert, always, invert’ that he used to solve the most complicated problems he faced.

The idea is as follows: flip the problem upside down; start at the solution and work backwards to where you are now. Begin at where you want to end up, consider everything that got you there in reverse order. In other words: define the outcomes you don’t want and plan the path to avoid hitting them.

Inversion exercises are used to help you figure out what you need to do to get to an outcome, as well as help you become aware on things you will need to get you to where you want to go. Pitfalls to avoid, skills you need to master and issues you will encounter along the journey. You need to think forwards and backwards.

Marcus Aurelius as well as other stoic philosophers called this premeditatio malorum — a ‘premeditation of the evils and troubles that might lie ahead’ — in other words — imagining the worst case scenario. Avoiding these mistakes sometimes is even more powerful skill than actually achieving success.

Charlie Munger put it best in ‘The Power of Not Making Stupid Decisions’, in which he says: “It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instead of trying to be very intelligent.”