Charlie Munger’s “Don’t Make Big Mistakes” Rule—The Underrated Key to Career Longevity
Most career advice is about optimization—how to be more productive, more visible, more strategic. But Charlie Munger, Warren Buffett’s intellectual partner, had a different approach.
Most career advice is about optimization—how to be more productive, more visible, more strategic. But Charlie Munger, the late billionaire investor and Warren Buffett’s intellectual partner, had a different approach:
“It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instead of trying to be very intelligent.”
In other words, don’t chase brilliance—just avoid catastrophe.
This idea is a form of via negativa, a mental model where instead of focusing on what to add, you focus on what to eliminate. At work, it translates to this: You don’t need to be the smartest person in the room—you just need to avoid major screw-ups that kill your reputation, trust, or career trajectory.
Let’s break down how this principle applies to your job, your projects, and your long-term career.
Big Mistakes at Work: The Silent Career Killers
Most careers don’t get derailed because someone lacks raw talent. They get derailed because of avoidable mistakes:
1. Breaking Trust – If your manager or teammates can’t rely on you, you’re done. This isn’t about being perfect—it’s about showing up, keeping your word, and not overpromising.
2. Recklessness with High-Stakes Work – Some tasks allow for trial and error. Others don’t. Pushing a Friday night deploy without a rollback plan? Bad idea. Handling security-sensitive data carelessly? That one mistake could haunt you for years.
3. Toxic Office Politics – Playing power games, backstabbing, or forming the wrong alliances can accelerate your downfall. Offices change. People remember. And past behavior follows you.
4. Repeated Unforced Errors – Missing deadlines, sending unreviewed emails, jumping into meetings unprepared—individually, these seem small. But when they become patterns, they add up to “not dependable.”
5. Publicly Blaming Others – Owning your mistakes earns respect. Deflecting responsibility destroys it. Even if you weren’t the only one at fault, take your share of the blame—people notice.
6. Ignoring Red Flags – Sometimes, the mistake isn’t what you do—it’s what you ignore. That project with no clear owner? That promotion opportunity with a boss who churns employees? Avoiding landmines is an underrated skill.
The Engineer Who Lost His Career Over One Bad Call
Let’s take a real-world example. There was an engineer—brilliant, respected, highly productive. But he made one devastating mistake:
During an incident, under pressure, he hardcoded credentials into the production codebase to resolve an outage. It worked. But a security review weeks later uncovered it. What happened? Immediate termination.
It didn’t matter that he had 10+ years of solid performance. One bad decision, under pressure, erased everything.
This is what Munger’s rule is about—avoid the kind of mistake that you can’t recover from.
The Power of Avoidance: Career Durability > Short-Term Wins
If you’ve worked long enough, you’ve probably seen people who:
• Were great at what they did—but got fired for poor judgment.
• Were decent at what they did—but stuck around and steadily rose through the ranks.
Why? Because survivability matters more than short-term brilliance. Here’s how to apply this mindset:
1️⃣ Use Inversion: Ask “What Would Get Me Fired?”
Munger loved inversion—flipping problems around to see them more clearly. Instead of asking:
“How do I succeed at work?”
Ask:
“What are the top ways people screw up their careers?”
A few answers come to mind:
• Being unreliable.
• Overpromising and underdelivering.
• Mishandling a sensitive situation (security, legal, ethics).
• Clashing with the wrong person in the wrong way.
• Becoming the person people don’t want to work with.
Now, just systematically avoid those things.
2️⃣ Don’t Take Unnecessary Risks on High-Stakes Work
Some projects allow failure. Others don’t. Be smart about where you take risks.
🔹 Code review? Experiment, try new things.
🔹 Deploying something that could bring down production? Triple-check, get a second pair of eyes, and if in doubt—wait.
The best engineers aren’t the ones who take wild risks and succeed. They’re the ones who know where they can afford risk—and where they can’t.
3️⃣ Think in Terms of Reputational Debt
Some mistakes have a long tail—they follow you.
• If you develop a reputation for missing deadlines, it’ll take years to undo it.
• If you’re known as someone who gets defensive under feedback, that stigma sticks.
• If you’re the person who causes outages, even one major incident can shape how people see you.
Every action either builds or subtracts from your reputation. Make sure you’re not accumulating reputational debt that you’ll have to repay later.
4️⃣ Be Boringly Consistent
People underestimate the power of simply being dependable. At work, the fastest way to get promoted isn’t to be a genius—it’s to be someone who always delivers without drama.
• If you say you’ll do something, you do it.
• If there’s a fire, you don’t make it worse.
• If you’re given more responsibility, you handle it without dropping the ball.
Careers are long. Survivability beats intensity.
5️⃣ Recognize That Some Mistakes Are Career Killers
Munger’s rule doesn’t mean avoiding all mistakes—it means knowing which ones actually matter.
🚫 Mistakes that don’t matter:
• A typo in an email.
• A slightly late task that doesn’t impact anyone else.
• Not knowing something (as long as you’re open about it).
🔥 Mistakes that can derail you:
• Mishandling security, finance, or legal matters.
• Publicly undermining leadership.
• Getting emotional in a way that damages trust.
• Making repeated, sloppy mistakes that make people lose confidence in you.
The difference between an annoying mistake and a career-ending one is whether it breaks trust.
The Long-Term Advantage of “Not Being Stupid”
Munger’s philosophy is simple but incredibly effective:
“People try to be smart. All I try to do is not be stupid.”
If you apply this at work:
✅ You’ll avoid being the person others have to clean up after.
✅ You’ll build a reputation as someone who’s dependable under pressure.
✅ You’ll stay in the game long enough to naturally rise through the ranks.
It’s not about being flashy. It’s not about making the perfect strategic moves.
It’s about eliminating the avoidable disasters that sink careers.
And in the long run, that’s what really separates those who last from those who don’t.
A Thought to Leave You With:
What’s the biggest avoidable mistake you see people making at work?