Mental-Models

Most of education teaches you what to think. Almost none of it teaches you how to think. Yet the quality of your thinking determines the quality of your decisions, and your decisions determine the trajectory of your life. Here are 10 mental models that fundamentally change how you approach problems. 1. First Principles Thinking Strip away assumptions. Reason from fundamental truths. Most people think by analogy: “This is like that, so I’ll do what others did.” First principles thinking asks: “What do I know to be absolutely true? What can I build from there?” ...

I was stuck on a database indexing problem for three days. The problem: Queries were slow. I’d tried different index strategies. Nothing worked. Then I went rock climbing. Completely unrelated to the database problem. Or so I thought. At the climbing gym, I watched an instructor teach a beginner: Instructor: “Don’t try to solve the whole wall at once. Look for the next handhold. Then the next one. Chain them together.” ...

For six months, I wrote every SQL query like this: SELECT * FROM users WHERE id = 123; SELECT star. Get all the columns. Always. My reasoning: “I might need all the data. Better to have it than query again.” This worked fine for my bootcamp projects. Tables had 5 columns. Performance didn’t matter. Then I joined a company with real production data. My first code review: Senior Engineer: “Why are you selecting all columns?” ...

Obscure methods and mental models that change how you think about thinking. Each one a tool most people never discover. The Zettelkasten Method Note-taking system that builds a “second brain.” The origin: German sociologist Niklas Luhmann used it to write: 70 books 400+ academic articles In 40 years He said his productivity came from his Zettelkasten (slip-box). How it works: Fleeting notes: Capture ideas immediately Literature notes: Summarize what you read (in your own words) Permanent notes: One idea per note, written clearly Link notes: Connect related ideas Index: Entry points to chains of thought The magic: Your notes become a thinking partner. ...

Small concepts that rewire how your brain works. Each one short enough to read in minutes, powerful enough to change everything. Forcing Functions Designing irreversible commitments that make failure impossible. Burn the ships. Make public declarations. Put money on the line. When Cortés arrived in Mexico in 1519, he burned his ships. His soldiers couldn’t retreat. They had to win or die. Modern versions: Tweet your goal publicly Bet money you’ll finish Sign a contract with financial penalties Delete the escape route The fancy term: Ulysses contracts - named after Odysseus who tied himself to the mast to resist the Sirens’ song. ...