Keep a record you cannot argue with
Memory rewrites effort in both directions, and neither version is useful.
Do this
Log the behaviour, not the outcome: sessions done, words written, weight lifted. One line, at the time. Review monthly rather than daily so you are reading a trend rather than a mood.
Why it works
Self-monitoring is a consistently effective component across behaviour change interventions, and a meta-analysis of goal-setting research found that monitoring progress improved attainment, with larger effects when the record was physically recorded or publicly reported.
Where it fails
Tracking can become the activity - elaborate systems that consume the time they were meant to protect. It can also worsen things where the measure encourages an unhealthy relationship with the behaviour, which is a real risk with food and exercise logging.
How you’ll know
If you dread opening the log, you are recording judgement rather than data. Simplify what you record.