One of the most important lessons I’ve learned: don’t believe anything completely.

As humans, we seek certainty. 

We are particularly talented at telling stories to help us maintain our certainty.

Justifying the purchase we made, our career path, our decisions.

We are storytellers, both in the way we describe things and how we remember and understand them. Linking events together in a logical way helps us remember things, and reassures us that we understand the world around us.

The problem is, none of those things are true.

Richard Feynman said “You must not fool yourself, and you are the easiest person to fool.”

The author Nassim Taleb agrees.

He’s shown repeatedly that as humans, we overestimate our understanding, constructing stories and narratives to fit events after the fact. We ignore extreme, unexpected events because they don’t fit our models of the world. 

There are a whole host of other studies showing similar psychological effects:

• We don’t deal well with extreme probabilities. 
• We don’t treat wins and losses the same. 
• And we don’t do well accepting that we don’t know.
  

The solution? 

Don't believe anything with certainty. There is always a level of uncertainty, whether we can assess it accurately or not. Having a blanket rule is easier. 

Erring on the side of uncertainty is likely to cause some mental discomfort. But it opens us to the possibility of other options.

Believing something with a high probability is okay. In most circumstances, it should be accepted as good enough.

But believing something with complete certainty closes us to the possiblity of another view, another reason, another answer.

And it makes us vulnerable to a whole host of other psychological mistakes.

I'd rather accept a little mental discomfort if it means I fool myself just a little bit less often.

As humans, we like the world in black and white. But there is no such thing.

We like to simplify the world. It makes life easier. We would never be able to function if each day we had to re-learn whether something was dangerous or not. Or whether someone was a friend or an enemy. 

So instead, we learn once, form a model in our heads, and run with it. 

We learn that stoves can be hot and we should treat them with caution. 

We assume that people who look, act, and speak like us are friendly. We are cautious of those who don’t. 

The problem is that we form these models even when they aren’t appropriate. And we don’t know when they aren’t.

It happens in politics all the time. We assume a specific identity based on the political party someone supports. 

While they likely share some views with that party, they are individuals. They likely have nuanced views in different areas. 

But that complicates our model, and it takes effort and patience to engage with someone to understand those nuances. Instead, we throw them all in the same bucket and treat them the same.

We accept and reject beliefs the same way. 

If someone from a group we dislike or oppose believes something, we tend to oppose it. Yet if we tried, we can almost always find something we agree on.

That’s the problem. The world is not made up of absolutes, of black-and-white scenarios. There are degrees of truth to almost everything. We can interpret the same information and come to very different conclusions.

The world is not black and white. There are no absolutes.

The world is full of shades of grey.

The best way to come up with good ideas: don’t get stuck on other ideas first.

Paul Graham’s excellent essay Keep Your Identity Small explores why thoughtful discussions about certain topics are difficult:

“I think what religion and politics have in common is that they become part of people's identity, and people can never have a fruitful argument about something that's part of their identity. By definition they're partisan.”

And he explains why that matters for idea generation:

“The most intriguing thing about this theory, if it's right, is that it explains not merely which kinds of discussions to avoid, but how to have better ideas. If people can't think clearly about anything that has become part of their identity, then all other things being equal, the best plan is to let as few things into your identity as possible.”

The link between your identity and your actions is so powerful that it’s a common habit-formation strategy. Simply saying you are a specific kind of person—the kind of person who exercises, for example—helps cement the habit. 

It’s something you can investigate for yourself. Next time you find yourself in an argument, try and slow down and examine how you feel when someone challenges your idea. You feel attacked! 

Even if someone asks a question about an idea, or a piece of your work, the visceral reaction is defensive. I feel it myself. It’s something that’s very hard to prevent, but we can learn to recognize and accept it.

If we have that kind of reaction in small arguments, it’s no surprise we react poorly when someone attacks part of our identity.

Keeping our identities small helps us have better ideas because we’re open to more possibilities. 

The reverse is also true. Allowing our identities to grow impedes our ability to think with clarity.

Thinking clearly is hard enough. 

We would do well to avoid anything that makes it harder still.

Ray Dalio cites this as his most fundamental principle:

“Truth —more precisely, an accurate understanding of reality— is the essential foundation for producing good outcomes.”

It’s not hard to understand why. If we fail to recognize reality, we work on the wrong things, spend time with the wrong people, and move in the wrong direction.

If we fail to recognize we aren’t performing at our job and change things, we’ll be fired.

Spend our lives in a relationship with the wrong person, and we’re going to be unhappy. 

As humans, we are built to see only the parts of truth we like. 

We are all full of biases. They cause us to think highly of ourselves, seek evidence that confirms our beliefs and avoid anything painful.

Overcoming these biases is hard work. 

It requires learning to recognize situations where we are vulnerable. Situations where we are subject to social pressure, or experiencing strong emotions.

It requires finding objective ways to evaluate ourselves, or having others do it for us.

Or using tricks like Extreme Ownership to short-circuit some of these natural reactions.

The reward, if we manage to do it, is that we see ourselves and the world more clearly.

Which means we can get closer to getting what we want from the world.

That helps us in all kinds of ways: 

• Finding the right job
• Working on the right things
• Finding the right partner
• Spending time with the right people
• Prioritizing the parts of our lives well
  

The reward for doing these things well is a happy, healthy life.

Which makes truth something worth working for.

Dating and sales are the same skills: the only difference is what you’re selling.

Dating and sales are both about communication skills:

• Building trust in a short amount of time
• Listening to the other person and making them feel heard
• Paying attention to their needs and fulfilling them
  

All our relationships are built on these foundations.

Our ability to communicate is a fundamental skill.

Improving your conversational skills will help your relationship with friends, colleagues, and parents. It also makes random interactions a lot more fun.

Improving your writing skills can give you an audience on the internet and earn you appreciation at work. It will also help you think.

Learning the ability to persuade others will help you everywhere. Getting colleagues to buy into a project at work. Negotiating with your partner or your kids. Building a partnership for your new company.

Improving communication skill is one of the few things which can impact your entire life.

It’s also one of the areas that consistently holds people back.

There are some jobs and some relationships where performance can overcome poor communication abilities.

But it’s a rare occasion where better communication wouldn’t help.