I'm obsessed with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵

1. Survivorship Bias: 1. Survivorship Bias:

We focus on the winners and ignore the losers.

We study the college dropout billionaires but ignore the thousands of dropouts who failed.

Success leaves clues, but failure teaches lessons.

PHILOSOPHICAL RAZORS are a mental rule of thumbs that "shaves off" bad explanations and stupidity in your decision-making.

Here are the 8 sharpest Razors to upgrade your thinking instantly: 🧵
1/ Occam's Razor

The simplest explanation is usually the correct one.

If you hear hoofbeats in Texas, think horses, not zebras.

Don't overcomplicate solutions. Complexity is often just a mask for confusion.

He was the most powerful man on earth:

Marcus Aurelius.

He wrote "Meditations" to keep himself sane while ruling an empire. He never intended for it to be published.

Here are 8 of his best short ideas from one of the greatest stoics in history:
1. The Obstacle is the Way

"The impediment to action advances action. What stands in the way becomes the way."

Stop wishing for things to be easy.
Use the challenge as fuel.

The struggle isn't blocking the path, it *is* the path.

I used to be stressed out of my mind and wasted years making terrible decisions.

Then I spent hours studying Charlie Munger’s letters to learn his mental models on decision-making & problem solving.

Here're are the top 5 I've collected: 🧵
Why do you need Mental Models?

Most people try to solve problems with raw intelligence. It's exhausting.

Munger says: "To a man with a hammer, everything looks like a nail."

You need a toolbox. Models don't tell you what to think, but how to think.

Here're Munger's best 5:

A "Paradox" is a statement that seems contradictory but actually contains a hidden truth.

Once you see them, your worldview changes forever.

Here are my 10 favorite mind-bending paradoxes that will upgrade your thinking & decision making: 🧵

1. The Paradox of Choice 1. The Paradox of Choice:

Logic says more options = more freedom. Psychology says more options = anxiety and analysis paralysis.

When you have too many choices, you are less likely to pick one, and less satisfied with the one you do pick.

Constraints create creativity.

I'm obsessed with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵 1. The Spotlight Effect:

We constantly overestimate how much people notice our appearance or mistakes.

The truth? Everyone is too worried about themselves to worry about you.

You are not the main character in their movie.

Mental models are rules of thumb that simplify any decisions.

Elon Musk is a big believer in it.

Not only Musk, but also Charlie Munger, Jeff Bezos, and Steve Jobs.

These are 7 of the most powerful mental models from history's greatest thinkers: 🧵 1. First Principles (Elon Musk)

Musk didn't accept that rockets had to cost $65M.

He looked at the raw materials: carbon fiber, metal, fuel. The cost was only 2% of the ticket price.

He realized the "high cost" was just industry inefficiency.

Don't copy; reason from physics.

I'm obsessed with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵

1. Survivorship Bias: 1. Survivorship Bias:

We focus on the winners and ignore the losers.

We study the college dropout billionaires but ignore the thousands of dropouts who failed.

Success leaves clues, but failure teaches lessons.

I'm obsessed with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵

1. Parkinson's Law: 1. Parkinson's Law

Work expands to fill the time you give it.

Give yourself a week? It takes a week.
Give yourself an hour? Done in 60 minutes.

The fix: Track task duration and energy levels ruthlessly.

I used to think people were rational.

Then I found FBI files on Hanns Scharff's "weaponized kindness" technique.

He extracted secrets from 480 Allied pilots without breaking a sweat.

Learn his mind-boggling techniques (they're the ultimate lesson in human nature):
Picture this: 1943, Nazi Germany.

A captured American fighter pilot expects torture.

Instead, his interrogator offers homemade apple strudel and asks about his hometown.

The pilot relaxes. Fatal mistake.

Meet Hanns Scharff - the man who weaponized kindness.

Mental models are rules of thumb that simplify decisions.

Elon Musk is a big believer in Mental Models.

Not only Musk, but also Charlie Munger, Jeff Bezos, and Steve Jobs.

I've collected 7 of the most powerful mental models from history's greatest thinkers: 🧵 1/ The Bloom-Bilal Rule:

When bored and lacking ideas, keep walking until the day becomes interesting. (via @sahilbloom + @bzaidi)

The most important skill to master for 2026:

Learning How to Learn.

Here's a 60-second system to learn and remember anything 10x faster (from a Nobel Prize-winning physicist)

The Feynman Technique: 🧵 This framework is from the Nobel Prize-winning physicist, Richard Feynman.

Known as "The Great Explainer," Feynman could break down quantum mechanics for non-scientists.

His secret? He didn't just memorize—he TRULY understood.

Rich people collect fancy watches.

I collect useful mental models—timeless rules of thumb that simplify decisions.

12 most powerful (and dangerous) mental models I've found:

1. The Power of Walking 1. The Power of Walking

When bored and lacking ideas, keep walking until the day becomes interesting. (via @sahilbloom + @bzaidi)

Yesterday, 3M people found my weird obsession with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

7 more of the most powerful (and dangerous) cognitive biases I've found: 🧵

1. Confirmation Bias: 1. Confirmation Bias:

We search for information that supports our beliefs and reject anything that contradicts them.

If you hate a specific politician, you only read news that makes them look bad.

You don't want the truth; you want to be right.

I'm obsessed with cognitive biases.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵

1. Survivorship Bias: 1. Survivorship Bias:

We focus on the winners and ignore the losers.

We study the college dropout billionaires but ignore the thousands of dropouts who failed.

Success leaves clues, but failure teaches lessons.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found: 🧵

1. Parkinson's Law: 1. Parkinson's Law

Work expands to fill the time given.

When we have more time, we tend to procrastinate and become inefficient.

A good reminder to track your task duration and energy level.

In 1905, a female scientist discovered the XX XY Chromosomes.

But a man stole her work and won all the acclaim.

She died in forgotten obscurity at just 50.

Here's how Nettie Stevens' discovery was stolen in daylight... 🧵
Born in 1861 in Cavendish, Vermont, Nettie Stevens broke all the rules for women...

Most women get married at 22.
Nettie chose education.

She worked 14 years as a teacher and librarian, saving every dollar.

At 35, she finally had enough to attend Westfield State Normal School...

In 1238, Granada's engineers pulled off the biggest feat in medieval history:

They built a self-sustaining water system 200 meters up a mountain.

No pumps. No electricity. No downtime. But what they created next nearly destroyed physics forever.

Here's the full story: 🧵 While other medieval cities fell to Christian armies during the Reconquista, Granada remained unconquered for over 250 years.

The secret?

The Alhambra Palace - a fortress of such genius engineering that even modern NASA scientists study its systems.

A "cognitive bias" is a systematic error in thinking that destroys decision-making.

11 most powerful (and dangerous) cognitive biases I've found:

1. Parkinson's Law: 1. Parkinson's Law

Work expands to fill the time given.

When we have more time, we tend to procrastinate and become inefficient.

A good reminder to track your task duration and energy level.

In the 1940s, Australia built a town on the deadliest dust in history:

They built a mine on newly discovered “blue gold.”

But what they created turned Wittenoom into the most toxic ghost town on Earth.

Welcome to Australia's Secret Chernobyl: 🧵 Wittenoom, Western Australia.

In the 1940s it looked like opportunity—a mining town built on “blue gold.”

Men came for work, families built homes.

What they didn’t know: the very air was laced with fibers that would one day kill them.

70 years ago, a woman discovered nuclear fission.

But her male colleague stole her work and won the Nobel Prize.

She fled Nazi Germany empty handed and died without a word.

Here's how the biggest theft in science buried Lise Meitner's name in history: 🧵
Born in Vienna in 1878, Lise Meitner fought to enter a field that actively excluded women.

Universities across Europe severely limited female students, especially in physics...