Last Tuesday I finished my 500th compressor swap since I started tracking in 2016. That number matters because my callback rate sits at zero for those jobs, which surprised me more than the count itself. I keep a simple spiral notebook with each unit's model, pressures, and the exact reason for failure, and that habit caught two bad capacitors that would have fooled me otherwise. The milestone also made me realize I've probably saved customers around $75,000 in repeat service fees, which is humbling to add up. Anyone else keep a long term log like this, or does tracking feel like extra busywork on the job?