What is prediction error?

Example: You launch a new weekly planning ritual. For the first month, three of your four weeks go smoothly — tasks complete on time, energy stays manageable. But one week collapses: you overcommit on Wednesday, skip Thursday's deep work block entirely, and finish Friday with a backlog larger than where you started. Most people focus on the three good weeks as validation that the system works. The single failed week contains more information. It reveals your system has no mechanism for handling unexpected load, no rule for when to decline new commitments mid-week, and no recovery protocol when a single day derails. The three successful weeks told you the system works under normal conditions. The failed week told you exactly where the system breaks — and those breakpoints are the precise locations where improvement is possible.

This concept is part of Error Correction in the How to Think curriculum.