Why Keeping a Decision Journal Will Make You Smarter

The Problem with Hindsight

When a decision works out, we think we were smart. When it doesn't, we think we were unlucky. This is outcome bias — judging the quality of a decision by its result rather than the quality of the reasoning at the time.

Annie Duke, former professional poker player and author of "Thinking in Bets," argues this is the single biggest obstacle to improving our decision-making.

What Is a Decision Journal?

A decision journal captures your thinking at the moment of decision — before you know the outcome. Each entry records:

1. What you're deciding and the options you considered

• Your reasoning — what information you based the decision on
• Your confidence level — how sure you are (as a percentage)
• What you expect to happen — your prediction
• How you're feeling — emotions can reveal hidden biases
• A review date — when you'll look back at this decision

  Why It Works

  Fights Hindsight Bias

When you review past entries, you see what you actually knew and believed at the time — not what your memory reconstructs after the fact.

Builds Calibration

Over time, you can compare your confidence levels to actual outcomes. If you say you're "80% confident" and you're right only 50% of the time, you know you're overconfident. This is called calibration — and it improves with practice.

Creates a Feedback Loop

Most people never learn from their decisions because they never formally review them. A journal with scheduled review dates forces the feedback loop that drives improvement.

How to Start

The simplest approach: after every important decision, spend 5 minutes writing down your reasoning and confidence level. Set a calendar reminder to review it in 30-90 days.

Our Decision Journal feature automates this entire process. Log your reasoning, set your confidence, schedule reviews, and watch your calibration score improve over time.