Someone once wrote that the problem with life is that it only happens once. It’s like an improvised theater. [1]
The sentence is about regret — the regret we feel after making decisions. We make a choice, only to find out later that there was a better solution. But we didn’t know it at the time. The challenge of life, for every person, is: how can I find the optimal solution, so I regret less later?
In life, there are things we know, and things we know we don’t know. But there are also things we don’t know that we don’t know. There's a widely accepted belief that to make better decisions, we need to expand what we know. But I think what really matters more is expanding the set of things we know we don’t know.
Here’s the pyramid of knowledge (drawn with ChatGPT’s help):
The things we know make up a small part of all the knowledge available to us. The second layer might be a little bigger, and the third — the things we don’t even know exist — is by far the largest. Every layer of the pyramid feeds from the one beneath it. The things we know today were once things we knew we didn’t know. And before that, we didn’t even know they existed.
For simplicity (and because writing and reading this paragraph wasn’t exactly easy), let’s abbreviate the three levels as follows:
- Level 1: K (knowns)
- Level 2: KK (known unknowns)
- Level 3: UK (unknown unknowns)
The problem
My hypothetical roommate and I are facing a critical challenge: Who should wash the dishes today?
Level 1 – Things We Know (K)
These are the things we’re good at. Our areas of expertise. The stuff we’ve practiced. I, for example, know a few things about software engineering. I know certain programming languages and use them regularly. I can ride a bike without thinking. But this knowledge isn’t permanent. It requires maintenance.
If I step away from the tech world for a while, maybe I can still write a simple program five years later — but I’ll definitely have lost a good portion of my knowledge. If I don’t use English for a while, I’ll probably forget a lot of words.
This first level of the pyramid requires energy to maintain. But it also sits at the top of our mental stack — it’s the fastest to access. It’s tiny. And humans seem to have a limited capacity to expand it. Adding new knowledge and keeping the old stuff alive is hard work.
So, my roommate and I agree that everyone should wash their own dishes — that way, we both suffer equally.
Level 2 – Things We Know We Don’t Know (KK)
There are technologies I’ve heard about, and I know a little about them, but I’ve never worked with them. I know I don’t know them. For instance, I know a few things about graph databases. [2] I’ve never used them in a real-world project, but I have a sense of what they are and what they’re good for. Or I know a bit about game theory — I know it’s useful for analyzing human, corporate, and political behavior.
This kind of knowledge is cool. It’s resilient over time, and it doesn’t need much upkeep. I can choose to dive deeper and move something from this level up to K, or just leave it here until I need it.
Someone once said, “When you have a hammer, everything looks like a nail.” The things in K are our hammers.
As level 2 expands, so does our toolbox. We know what we don’t know — and we have a rough sense of what those unknowns are. Now I might think: Maybe I should model the dishwashing problem using game theory? Or: Maybe a graph database is a better choice for this social-media-like project I’m working on?
Level 2 helps us pick how to solve a problem. The actual solving? That happens with Level 1 knowledge.
So I decide to study game theory. I pull it up from KK to K and solve my dishwashing dilemma.
The major difference between experienced and inexperienced people lies in the size of their level 2 knowledge. People might be equally skilled (K), but a more experienced person has a much broader KK — and that makes them better at solving problems and giving advice.
In software engineering, this is the core difference between a mid-level and a senior engineer. The senior has access to a wider set of tools, built up through years of exposure. The path from mid-level to senior is about growing that second level.
Level 3 – Things We Don’t Know We Don’t Know (UK)
This is where all the knowledge of the world lives.[3] The world is full of things we don’t even know could exist — and knowing about them could unlock new ways of solving our problems.
Most of the challenges people face — in life, relationships, work, even gaming — have probably been encountered and solved by someone else over the last 10,000 years. But we don’t know those solutions exist. And if we did, we’d probably handle life better.
Maybe if my roommate and I had known that dishwashers were a thing, we’d both be much happier now.
So, how do we bring things up from UK to KK?
Searching won’t help. You don’t know what to search for. You have to expose yourself — put yourself in the path of unknown knowledge.
- Listen to podcasts.
- Go to events where you don’t know what the title even means.
- Talk to the people you meet there.
- Read blogs by people who seem to solve problems better than you.
- Subscribe to newsletters.
We’ll never know everything. But we can grow our mental toolbox.
If we know what we don’t know, we increase our chances of making better decisions.
And if we put ourselves in front of what we don’t know we don’t know, that’s when real discovery happens.
I think the quote is from Slowness by Milan Kundera, but I couldn’t be sure. ↩︎
A graph database is a type of database composed of two main parts: entities form the graph’s nodes, and edges represent the relationships between those entities. ↩︎
The ferry bombing scene in The Dark Knight is an example of this. The Joker was trying to bring something people didn’t know about humans up to the second level of the knowledge pyramid. ↩︎