Core idea: Most productivity systems fail not because they are too simple, but because they are too complex to maintain past week two. Supporting points: 1. Complexity has a maintenance cost that compounds — every extra field or category is a tiny tax on every single day. 2. The systems that survive are the ones that need zero setup decisions once they are running. 3. "Good enough and used" beats "perfect and abandoned" every time. Quotable line: "You don't need a system smart enough to handle every edge case — you need one dumb enough to survive a bad week."