Play someone a song they've known for fifteen years, after they've spent a month learning bass, and they'll hear a line running underneath it they never once noticed. The line was always there. The ear wasn't.
None of this is about acquiring beauty or creativity. It's about developing an ear for what has been playing the whole time.
Awareness comes in increments too small to see daily. Then one week you catch yourself making something without calling it a waste of an evening, and realise the hearing has changed.