Use this template when
- You made a decision that cost time, money, or a customer.
- You can name what you do differently now.
- The lesson would help someone a year or two behind you.
The template
Replace each bracket with your own material. Delete any line that doesn't fit your story.
[One sentence: the decision you made, stated plainly.] [What it cost. Use a number: weeks, dollars, customers.] [Why it seemed right at the time. One or two lines. Be fair to your past self.] [The moment you realized it was wrong. A specific scene or conversation.] [What you do differently now. A rule or habit, not a platitude.] [Optional: a question for readers who've faced the same choice.]
A completed example
We spent six weeks building a feature before showing it to a single customer. It cost us most of a quarter's roadmap. At the time it felt responsible. We wanted it polished. We didn't want to waste anyone's time with something half-done. Then we demoed it. The first customer said, “Oh, we solved that with a spreadsheet.” The second said the same. Now nothing gets more than a week of work before someone outside the team sees it. Usually it's a screenshot in a Slack DM to three customers. What's the smallest thing you could show a customer this week?
The cost (six weeks, most of a quarter) and the new rule (one week, three customers) do the work. The middle section keeps it honest rather than self-punishing.
Tips
- Keep the lesson narrow enough to act on.
- Avoid ending with “Lesson learned!” The rule is the lesson.
- If other people were involved, tell your side without blaming them.
The example names, companies, and numbers are illustrative.