10 Clear Thinking Lessons That Changed How I Make Decisions

Inspired by Shane Parrish’s Clear Thinking

I’ve followed Shane Parrish’s work for years. His podcast The Knowledge Project is packed with conversations that stick with you. And his latest book Clear Thinking gave me something I didn’t realise I was missing: a framework for better decision-making.

Not just for high-stakes business moves or “life-changing” moments. But for the everyday stuff. The little yeses that cost you energy. The habits that shape your week. The voice in your head that says just push through when what you really need is to pause.

Shane’s background as an intelligence agent turned investor gives him a unique lens. People often call him “the spy who helps Wall Street think smarter.” But what he really teaches is how to think more clearly — in a noisy, reactive world.

Here are 10 takeaways that stayed with me:

1. Start with agency
You can’t control every outcome — but you can control how you respond. Focus on your process, not the result. That’s where your power lies.

2. Make room to think
Busy schedules lead to scattered thinking. Clarity needs space. Block time to step back, reflect, and actually think.

3. Don’t say yes too fast
“Let me think about it” is a full sentence. Most urgency is performative. Build buffers between input and decision.

4. Fix your defaults
We don’t rise to our goals — we fall to our habits. Your reactions when you’re tired, stressed, or under pressure? That’s your real default. Start there.

5. Know your internal enemies
There are four: ego, emotion, social pressure, and inertia. Learn to spot them when they hijack your thinking. Name them. Move anyway.

6. Build clarity through discipline
Clear thinking isn’t just about mindset — it’s about reducing noise. Routines help. Think: morning walks, screen-free time, fewer tabs open (literally and mentally).

7. Write your own rules
Friction eats energy. Create personal policies like “no meetings before 10am” or “don’t make decisions on the spot.” Fewer decisions = fewer regrets.

8. Be radically accountable
Accountability isn’t just about fixing mistakes. It’s about claiming your strengths and your blind spots. No outsourcing. No excuses.

9. Remember memento mori
We avoid thinking about mortality — but that’s what gives life clarity. When you remember it’s all temporary, the noise fades. What matters gets sharper.

10. Clear thinking is a skill
You weren’t taught how to think — but you can learn. Like any muscle, it gets stronger with practice. Read, reflect, repeat.

Why this matters

So much of modern life is reaction. Notifications. Meetings. Opinions. Pressure. We’re taught to perform, not to think. But good decisions come from clarity — not hustle.

What I love about Shane Parrish’s approach is that it’s not about becoming perfect. It’s about becoming more conscious. Learning to pause. Choosing better, one small moment at a time.

Whether you’re navigating your career, your finances, or just your Monday morning, learning how to think clearly is one of the most underrated skills you can build.