What does it mean that decision journals?

Record decisions, their reasoning, and their outcomes to improve future decision-making.

Example: You decide to hire a contractor instead of a full-time employee. Before you send the offer, you open your decision journal and write: the decision, today's date, the three reasons driving it, the outcome you expect in six months, and your current confidence level (70%). Six months later, you revisit the entry. The contractor left after four months. Was the reasoning flawed, or did an unforeseeable event intervene? Without the journal entry, you'd rewrite history — convinced you 'always had doubts.' With it, you can see exactly what you believed and why.

Try this: Open a notebook or document. Write the heading 'Decision Journal — Entry #1.' Record a decision you made this week or are about to make. Include: (1) the date, (2) the decision itself in one sentence, (3) three reasons driving the decision, (4) what you expect to happen, (5) your confidence level as a percentage, and (6) your current mental and emotional state. Set a calendar reminder to review this entry in 30 days. When the reminder fires, write what actually happened next to your original prediction.