A better system remembers the lesson when the person who learned it is absent.

Lessons live inside people by default, and people move on, take holidays, and forget. When the only record of a hard-won fix is somebody’s memory, the group relearns it every few years at full price. Writing it into the process, the checklist, or the default setting is how a group keeps what it already paid for.

After the next problem is solved, spend ten minutes putting the lesson somewhere outside a head. A line in the document, a changed default, a step in the routine. Ask whether a newcomer would meet the lesson without meeting you.