July 17, 20261 min read
Finance isn't as complex as we're taught.
Finance isn't as complex as we're taught.
There are simple financial heuristics that make it very digestible, but most people don't know they exist.
For example, the 20/3/8 car rule.
When buying a car:
• put down 20% or MORE
• finance it for MAX 3 years (36 months)... or less
• keep total payments BELOW 8% of gross monthly income
Our problem isn't the math. Copy/paste your income into Chatgpt and it'll do the calculations in seconds.
Our problem is our psychology. We chase what we want, not what we can comfortably afford. When those occasionally overlap, it usually due to coincidence.
Reread the bullets above.
I called out the more important details in all caps.
The numbers grabbed our attention.
The constraints are what matter most.
A simpler heuristic that overrides the 20/3/8 rule:
buy what we can afford.
• 100% down
• 0 years financed
• 0% of gross monthly income
Again, our psychology is the problem. The type of vehicle to can buy with cash is rarely the one we'd get if we had 5-10x as much.
Which leads to one last heuristic, for business owners:
You can make a living selling people what they need.
You can make a fortune selling people what they want.
Finance isn't complicated.
People are.