Life can improve while appreciation decreases; guard against that trade.

Improvement and appreciation can move in opposite directions, and often do. Each gain gets absorbed into the new baseline, so the standard rises just as fast as the circumstances, and you end up better off and no more satisfied. It is a quiet trade that nobody agrees to on purpose.

When something in your life improves, mark it deliberately before it becomes normal. A moment of actual notice at the point of change is what keeps the gain from disappearing straight into the baseline.