Mental Model or Get-Wise-Quick Scheme?
It can be irresistible, especially for some knowledge workers whose main output is judgment, to click the link promising to "improve your decision making with the most important mental models you need to know." However, most reading I've come across on mental models (which seems endless) is a get-rich-quick scheme for your brain "Learn the shortcut with this shortcut."
We all use mental models whether we know it or not, and being deliberate about applying them and acquiring more is a powerful thing - but mis-applying a mental model is just as bad as not having it in your inventory.
Mental models exist to simplify the world and allow us to make decisions in the face of impossible complexity. They consist of universal or local truths that surface as a result of deep exploration of a given domain or craft.
Here's a famous quote cited by many internet gurus and militant Munger-ites:
“You must know the big ideas in the big disciplines and use them routinely – all of them, not just a few. Most people are trained in one model – economics, for example – and try to solve all problems in one way. You know the old saying: To the man with a hammer, the world looks like a nail. This is a dumb way of handling problems.”
When Charlie Munger says to use mental models, he's saying that you can fall into traps by ignoring universal truths from other domains that you wouldn't otherwise be exposed to in your own discipline. Reading widely and pursuing worldly wisdom, then, is a shield against ignorance. It's playing defense so that you don't over-fit a single model to all your problems, not playing offense to try and find the correct shortcut. In fact, there are so many heuristics out there you are bound to find two that are at odds with each other for any given decision.
James Clear says, "You don't rise to the level of your goals. You fall to the level of your systems." And our systems are heavily rewarded for explaining as much about the world as we can with as little mental effort as possible. You have to fight a slew of mental biases to deliberately apply mental models and not be a man with a hammer. You want to end up looking more like this guy.
The way to get yourself a whole tool vest, as opposed to just a hammer, is to build the proverbial latticework of mental models on which to hang all the data points you gather. But just reading "Occam's Razor - the most likely explanation is the simplest one," and stashing it away in your notes app is going to build a weak link on that latticework.
Similar to reading a book summary rather than the actual book - you can get the main points, but you won't really internalize the message to the point where you can make use of it. Most of the time, the author wrote a whole book about those main points for a reason. If it's worth knowing, it's worth reading the book.
Don't get me wrong, I want to build my working collection of mental models, and I understand their effectiveness. I'm just expressing a gripe with the common literature on the subject, which I think attracts more clicks than it contributes wisdom.