Three years of a "lessons learned" document. Then I made the same mistake twice.

After every project I wrote what went wrong and what I'd do differently. A growing document of wisdom. Then I repeated a mistake from two years earlier and realized I'd never once opened it. The reflection had become a ritual not a resource. I started reviewing it monthly and the same mistakes finally stopped repeating.

The habit wasn't bad. I was writing lessons instead of applying them.

For those who keep lessons documents was it the format's fault or the lack of review? And what lesson have you written down more than once because you've never actually acted on it?