First Principles Thinking: Why You Should Ask Questions Like a Child

First Principles Thinking from a Child's Perspective

My nephew is five.

Like every five-year-old, he questions everything.

“Why is it bedtime?”

“Because it's dark and time for you to get some sleep,” replies his dad.

“Why does it get dark?” often followed by “Why do I need to sleep?”

His Dad answers the questions, but it's not long before his patience disappears.

“Because it does,” comes the blunt end to the questioning.

How Children Ask “Why?” Differently

Like most five-year-olds, my nephew’s brain is a sponge.

If the first answer doesn’t make sense, they keep asking until it does.

A child isn't doing this to be awkward; they just want to understand.

First-principles thinking is their default; they keep digging until the explanation fits what they see.

Most of your team once questioned like this, too.

Richard Feynman's quote captured this well:

"If you can't explain it to a six-year-old, you don't understand it yourself."—Richard Feynman

Sadly for us, school and work remove this style of learning. Memorisation becomes the dominant way we learn.

Knowledge becomes more important than understanding.

And when that happens, your decisions rest on what you remember, not what you truly understand.

From Knowledge to Understanding: Why Knowledge Isn’t Enough

From our first day at school, knowledge overcomes understanding.

This continues at work, with standard operating procedures defining how we complete tasks.

Memorisation wins...that is, until something goes wrong.

Then it's understanding that reveals the solution.

A problem with our repair management system brought this home to me.

The system worked fine until growth overloaded it.

The people who knew the system well could see the effects of the problem. But they had no understanding of why it was happening.

I was new, so I didn't understand. So I asked question after question until I understood the fundamentals.

Then we were able to identify the root cause and take action to fix it.

Knowledge lets you repeat what worked yesterday. Understanding is what lets you change it when tomorrow looks different.

‍

How to Ask Questions Like a Child (As an Adult Leader)

Children love asking 'why'.

It enables them to keep breaking the thing down until the explanation fits what they see.

This is first-principles thinking at its simplest.

As an adult, you accept surface answers. You draw on the dashboard's insights when making decisions, without question.

Standard operating procedures pull you back to whatever has been done before.

Confirmation bias means you search for numbers that back the story you believe. Time pressure and the urge to look competent push us to reason by analogy.

We do what worked last time.

But unless you built the dashboard, you won't know what it's not showing you when performance drops.

That’s when you’re managing the numbers, not the reality underneath.

You can't question everything. So you need the awareness to recognise recurring issues or high-stakes problems.

That's when you need to open a child-like 'why' loop to discover what's going on.

In those moments, you can use a simple first‑principles question framework to think like a child without acting like one.

A Simple First Principles Question Framework

You look to solve problems by analogy.

Anchored to previous problems, you will apply the same solutions again.

It feels safe, appears confident, and comes from your experiences. In truth, you're trapped in old assumptions.

To really solve a problem, you need to strip it back to basics and rebuild it from first principles.

Here's how:

1. Name your assumptions: Write down what you’re treating as facts about the problem (“customers won’t pay more,” “IT can’t change this system”).
2. Break the problem apart: Split it into core pieces—inputs, process, outputs, constraints.
3. Ask “why” at each piece: For each part, ask why it works this way and what basic truth it rests on.​
4. Reconnect to the original purpose: Ask, “What was this system or process meant to achieve in the first place?”
5. Rebuild from the goal: With those basics in view, design a new option that serves the goal without assuming the old constraints must stay.

Children simplify this by asking 'why?' again and again.

As a leader, you can ask questions like a child, only now you're doing it with a notebook and a decision on the line.

First Principles in Action: Elon Musk and SpaceX

Before SpaceX built rockets, Elon Musk tried to buy one from Russia.

The flight back from the unsuccessful sale prompted Elon to do something most of us wouldn't do.  

But what exactly did he do differently, and how can you copy that as a leader?

He began questioning what everyone else took for granted.

Elon realised assumptions dominated space travel:

• Rockets are single‑use
• Only incumbents can supply
• Costs are 'just how it is'

Whether from NASA or Russia, the cost of launching a rocket made travelling to Mars too expensive. Elon needed to find a way to make space launches cheaper.

First principles thinking let Musk ask one fundamental question:

Why are rockets so expensive, if they’re mostly steel, fuel, and electronics?

By pricing the raw materials against the finished cost of a rocket, Elon found a vast gap.

It showed there was room to build rockets for a fraction of the going price.  

You don’t need to run a space company to use the same pattern; you can borrow three simple principles.

What You Can Borrow Without Being Elon Musk

Musk's success with SpaceX came from a pattern you can copy, not from an IQ you can't.

Here are three examples of how to apply first principles thinking:

• Question the requirements: What are we treating as fixed—budget, timing, channels, rules—that might just be habit?
• Price from inputs, not history: If we rebuilt this from scratch using today's tools and knowledge, what would the cost drivers be?
• Design around the goal, not the legacy process: If our only goal was ..., how else could we achieve it without our current process?

These are the leaders' equivalents of a child's 'why?'

And it's here Musk's playbook rests.

It's the combination of the first-principles steps seen earlier with these actions. It's first principles thinking on a human scale.

Bringing First Principles into Your Next Decision

First‑principles thinking is a mindset shift.

You move from accepting the story on the dashboard to asking what’s really happening underneath.

You've gone from knowing the facts to understanding the problem. This improves your decisions because you're breaking the connection with your assumptions.

And that's the real upside to first principles thinking and child-like questioning.

It also unlocks deliberate thinking.

Assumptions allow us to be automatic —that is to say, fast — with our decisions. Slow thinking gives us the space to pause, list our assumptions, and ask why they should still hold.

This child-like skill lives in us all.

So, why don't you:

1. Choose one important decision this week.
2. Write down three things you’re treating as facts about it.
3. For each one, ask: “Why must this be true?”
4. Use the answers to revisit the problem with your first‑principles framework.

This turns your next decision into a live test of first‑principles thinking.

You already practised this as a child; you just pointed your questions at bedtime instead of budgets.

The opportunity now is to point that same curiosity at your next decision.

‍

‍