Mistake Ledger
Write the expectation first.
One page. For every decision that matters: the date, what we decided, what we expect and by when, what happened, and the rule we would add.
Why
A startup is a poor teacher: feedback is slow and noisy. Writing the expectation first makes it slightly kinder.
Founder Indus: Why smart founders repeat the same mistakeThe repeat-mistake rate
The share of entries that repeat a mistake type already logged. It should fall each quarter. A mistake type seen twice becomes a line on your own checklist.
Download the template (Excel)| Date | What we decided | What we expect, and by when | What happened | Mistake type | The rule we would add | Actions |
|---|---|---|---|---|---|---|
| Sample2026-07-01 | Build version 2 before taking pre-orders | 20 pre-orders by 31 July | 0 pre-orders; time spent on features | Building before the demand gate | No new version before the stage 2 proof file exists | |
| Sample2026-07-15 | Order 500 units from a vendor by phone, paid upfront | Delivery by 15 August | Not delivered by 15 August | Vendor terms not written | Every order on a written purchase order with a date and penalty | |
| Sample2026-08-05 | Ask 10 shop owners "would you buy this?" | 10 likely buyers | 8 said yes; 0 paid a deposit | Counting compliments, not commitments | Ask about the last time and what they paid; count commitments |
Your repeat-mistake rate
Add lines with a mistake type to see it. Sample rows are not counted.