You made a decision. It worked out - or it didn't. But do you remember why you decided that way? What you knew? What you were uncertain about? Without a record, hindsight rewrites history. You can't learn from decisions you've misremembered.
The journal captures reasoning before outcomes corrupt memory.
Write it down when you decide. Review it when you know.
What To Record
The Decision
What are you deciding? State it clearly. "Hired X over Y for the engineering role." Specific enough to evaluate later.
The Date
When did you make this decision? Timestamp matters. Your information state changes over time.
The Context
What did you know when you decided? What information did you have? What didn't you know? Capture the fog of the moment.
The Reasoning
Why this choice? What factors mattered most? What alternatives did you consider and reject? Your logic, not just your conclusion.
The Confidence
How sure are you? 60%? 90%? Quantify it. Vague confidence can't be calibrated.
The Expected Outcome
What do you expect will happen? What would "success" look like? What would "failure" look like? Define the test.
Learning From Outcomes
Schedule The Review
When you write the entry, set a date to revisit. Put it in your calendar. Without scheduled review, journals become graveyards.
Read your original entry before evaluating the outcome. Notice where you were right. Notice where you were wrong. The goal is learning, not self-criticism.
Separate Process From Outcome
Good decisions can have bad outcomes (bad luck). Bad decisions can have good outcomes (good luck). Evaluate your reasoning, not just the result.
Update Your Calibration
Were your 80% predictions right 80% of the time? Track your accuracy by confidence level. Over time, patterns emerge.
The Psychology
Defeats Hindsight Bias
"I knew it all along" is a lie your brain tells. The written record proves what you actually knew. Hindsight bias makes learning impossible; the journal defeats it.
Forces Clarity
Writing crystallizes vague thinking. If you can't articulate your reasoning, you don't have reasoning. The act of journaling improves the decision itself.
Creates Accountability
Future you will read this. That awareness sharpens thinking. You're committing to a position on the record.
Reveals Patterns
Individual decisions seem random. Collections reveal tendencies. "I'm consistently overconfident in hiring" only emerges from data. The journal is the data.
Making It Stick
Lower The Bar
You don't need to journal every decision. Start with consequential ones. Hires. Investments. Strategy pivots. The ones worth learning from.
Keep It Short
Five minutes per entry is enough. A terse record beats no record. Perfection kills consistency.
Make It Searchable
Tag by domain, by type, by outcome. Future you needs to find patterns. A pile of notes isn't a journal - a queryable archive is.
Decide, then journal. Always. The gap between decision and documentation is where entries die. Make it part of the decision process, not an afterthought.
Most people trust their memory. Most memories are wrong. The decision journal is how you stop fooling yourself.
Write when you decide. Review when you know. Learn what you're actually good at - and what you're not. Calibration is wisdom. The journal is how you get there.
You can't learn from decisions you've misremembered.