As a lifelong photographer, I have, over many decades, developed a practiced eye.
What's that mean?
Simply that my eye/brain connections are wired to see through the camera's viewfinder in such a way that good composition feels natural. (If you're interested, you can see my photo gallery here).
In the same way, we, as audiophiles, have developed what I like to think of as the practiced ear. We have trained ourselves to know what to listen for and what to do if we're not hearing what we want.
Certainly, one needs the right equipment and musical sources from which to effectively evaluate what comes out of our stereo systems, but what we hear is backed up by (often) many years of experience.
The practiced ear. It's something each of us has developed over time and something valuable. We've earned our ears.