How can personal decision-making utilize first principles to filter out external noise?

Friend, this is an excellent question, one that feels unavoidable in our daily lives. When you have to make a big decision, like changing jobs, choosing a city to develop in, or whether to get married, your relatives, friends, colleagues, and various "gurus" online will all offer advice, making your mind feel like a chaotic mess. At times like these, "First Principles Thinking" is a Swiss Army knife that can help you clarify your thoughts.

Let's first talk about what "First Principles" means in plain language; don't be intimidated by the name, it's actually quite simple.

Imagine you're a chef.

How do most chefs (which is how most of us operate daily) cook? They look at recipes, or watch how others do it, and then imitate them. For example, "Everyone puts star anise in braised pork, so I will too." This is called "reasoning by analogy", which means referring to others' methods. There's nothing wrong with this; it's efficient and less prone to major errors.

But how would a "First Principles" chef think? They would ask:

What is the essence of a dish? It's a combination of ingredients, flavor, texture, and nutrition.
What is the soul of braised pork? It's making the pork "not greasy, tender, soft, and perfectly balanced in sweet and savory flavors."
What role does "star anise" play here? It removes gamey odors and enhances aroma.
Are there other things I can use to remove gamey odors and enhance aroma? For example, instead of star anise, could I use bay leaves and cinnamon? Or if I use a bit of lemon juice and beer to remove the gamey taste, would it create a completely new flavor?

You see, they're not just imitating a recipe; they're starting from the most fundamental question, "Why is this dish delicious?", and then recreating their own recipe. This is First Principles Thinking—breaking things down, returning to the most basic, core elements, and then recombining and rebuilding from these fundamental elements.

Alright, now that we understand this, let's see how to use it to "filter out external noise."

The so-called "external noise" is essentially those "ready-made recipes" that others give you. For example:

Parents say: "Quickly take the civil service exam; it's stable, an iron rice bowl!"
Friends say: "Don't go to big cities; the pressure is too high, you can't compete!"
Social media says: "You must earn a million a year before 30, otherwise you're a failure."
Consumerism says: "You need to buy this latest model phone/bag to reflect your worth."

These are all "conclusions" that others have drawn based on their experiences, values, or interests—in other words, "someone else's recipes." Using them directly might be okay, but it's very likely not to suit your "taste."

Applying First Principles to filter noise can be broken down into three steps:

Step One: Deconstruct the Problem, Find Your "Atoms"

When a decision is before you, don't rush to choose between A and B. First, break down the problem itself and ask yourself: What do I truly want? Strip away all the fancy packaging to find the most core, irreducible "atoms of your needs."

For example: You're debating whether to "quit your stable job to join a startup."

Noise will tell you: "Don't be silly, stability is most important!" or "Go for it, youth is for taking risks, what if you achieve financial freedom?"
First Principles will make you ask yourself:
- I spend 8+ hours working every day; what do I truly want to gain from work? Is it "security"? Is it "high income"? Is it "skill development"? Is it "the satisfaction of doing what I love"? Or is it "impact on others"?
- Rank these things you want by importance. For example, you might find that for you, the three most important "atoms" are: 1. Rapid personal skill development; 2. Autonomy in your work; 3. Reasonable income to secure your livelihood.

You see, once deconstructed like this, the problem is no longer "stable job vs. startup," but rather "which option better fulfills these three core needs of mine."

Step Two: Relentlessly Ask "Why" for All "Noise" and Assumptions

Now that you have your "atoms of needs," you can begin to scrutinize external noise. For every piece of advice you hear, question it like a curious child, asking "why."

Continuing with the example above:

Noise 1: "Civil service/state-owned enterprises are the most stable!"
- You ask: Why is it stable? — Because you won't easily be fired.
- Then ask: Does "not being fired" equate to the "security" I desire? If I stay there for ten years, day in and day out, with no skill improvement, while the outside world changes drastically, what if policies change one day or I want to leave? Would I then lose my ability to survive in society? Is that true "security"?
Noise 2: "Startups are too risky!"
- You ask: What does "high risk" mean? — It could mean the company might fail, or I might get very tired.
- Then ask: If the company fails, what does that mean for me? — I'd be unemployed. But if, in one year at this company, I learn more than I would in three years at my previous job, and my skills improve significantly, wouldn't it be easier for me to find my next job? Is this "growth" itself a form of risk mitigation? And "tiredness"? Can I accept the hard work required for growth?

By constantly asking these questions, you'll discover that many "self-evident truths" people speak of are actually built upon a heap of assumptions that may not apply to you.

Step Three: Reconstruct Your Answer Based on Your "Fundamental Facts"

After the first two steps, you've broken down the problem into your "atoms of needs" and debunked various "taken-for-granted" assumptions within the external noise. Now, you can start "cooking" your own solution.

Your core needs are: 1. Growth; 2. Autonomy; 3. Reasonable income.
The facts after your scrutiny are:
- Your current "stable" job offers slow growth, low autonomy, but guaranteed income.
- The "startup" offers rapid growth, high autonomy, but potentially unstable initial income and the risk of company failure.

Now, assemble your decision. This decision is no longer a simple either/or; many new, tailor-made options might emerge:

Option C: Can I talk to my current boss and try to get a more challenging, autonomous project to lead? If so, I could balance "stability" with "growth/autonomy."
Option D: Can I not resign yet, and instead use my spare time to participate in some startup projects or try building a small product myself? This way, I can learn and grow while also reducing risk.
Option E: If I decide to join a startup, how much savings do I need to prepare for potential income interruptions? Can I negotiate a "base salary + stock options" plan with them to balance risk and reward?

See? Through First Principles, you're not passively accepting noise; you are actively designing your own life path. Your decisions are based on your own core needs (your "atoms") and an independent judgment of facts, not on others' opinions.

To summarize:

First Principles is like a built-in "noise-canceling headphone." When the outside world is noisy, you put it on, and you can:

Deconstruct the problem, and hear your truest inner voice (what do I really want?).
Question assumptions, reduce others' opinions and advice to their most basic facts, and see if they hold up (Is what they're saying true? Is it right for me?).
Reconstruct, using these fundamental facts that belong to you, to build the solution that best fits you.

This thing is like fitness; you need to practice it a lot. The next time you face a difficult choice, try this method. By not being swayed by others' rhythms, you'll find your decisions become much clearer and more resolute. Because you'll know that this answer is one you crafted for yourself, unique to you.