I was thinking about this and realized it's all in my brain. My ears are not improving. What gets better is my brain's ability to process the quality and characteristics of the sound. My brain compares the sound I heard before and I am hearing now and it teaches me to appreciate the differences.
Exactly. It's called learning and learning increases enjoyment! [FWIW, I like the word "mind" (the part of you with language, judgement, interpretation) instead of brain (neurons, blood vessels, etc.) but that's a technicality.]
It is what you think about your sound that matters.
Nobody else.
Maybe that holds for you, but it was other people who helped me hear new things. If I was left to only myself, I'd still be listening to a far inferior system. They said things like,
"Listen for the 'soundstage' and see if you can tell the instruments' position on the stage."
Or they said,
"Listen to the difference between a clear, taut bass and a boomy/muddy one."
"Oh, now I get it," I said. "Thanks for helping me hear a difference I wasn't hearing before."
Turns out it was not just about what I heard. It was what other people could hear that I couldn't hear yet. They taught me to hear better.
Maybe you think that every man is an island when it comes to the achievements of audiophile taste; in my experience, it takes a village.
