And I recognize that some changes that make me smile at first can make me cringe later...
Discerning a positive or negative change in a system
Over the past year I have changed my entire system save the speakers, subwoofers, and streamer. I have not always made one change at a time, listened for an extended period and then decided if and what the changes might be. I was having too much fun buying stuff. In any event, whether it was one or a few changes at a time, I have tried to identify more depth, clearer imaging, better highs, smoother bass, yada yada, yada.
As I listen to my latest changes (new interconnects and some tweaking to my crossover) I am struck by how I notice instruments that were previously merely background sounds, am startled by a voice or chord I was not expecting, or can more clearly identify a source that before had been amorphous. All made me smile. I have also made changes that have made me cringe.
To me, it's not that one can identify what the change is but whether you experience the music differently with it. It does not matter what “it” is, but rather how you react to “it”. If I hear something new on an old recording and it makes me smile and get deeper into the music, the change was good and no further "analysis" is needed.