Had a somehow similar experience with Strava. I am biking these days only to commute - so doing the same boring 15km urban route 2, 4 or 6 times a week (Returns). Each time my performance would be driven by the weather, my load (public library books weight a ton), fatigue state after a long word day or a poor night, traffic, roadwork etc...not by my training consistency or motivation. Yet the app would keep notifying me of new records beaten each time to keep me engaged by shortening time after time the distances measured,resorting down to timing every single "one block long" segment between traffic lights, stop signs or various landmarks to find new records to beat :(

"your best time is now 41sec (instead of 42 2 years earlier)" -> that's when I stopped completely using it.