Is anyone willing to entertain the idea

the human power to differentiate between tiny gradations is enormous, but doing the comparison is where it gets tricky. take color, for example: people can see differences between incredibly close shades/tints if they are side by side, but not if seen in separate contexts. I would maintain that it's the same with audio: you need to be able to A/B so you're not relying on your memory of what your system/component sounded like before the change. why is this so contentious? if you have a system where you can go back and forth between two variables and you don't hear an 'improvement' (let's not even get into defining that), why waste your money? if you can hear a desired change, who cares if someone else tells you you're 'wrong'. it's your money and your system!

I know all the things that I could/should listen for and how to identify them, but the one test that never fails me is: do I hear things in well-known source material that I never heard before?

After spending two weeks at the Betty Ford clinic and a week at Gamblers Anonymous, I'm betting that I start drinking again. At least when I hear the imaginary differences in my audio system the voices in my head are drowned out for an hour or so.

I hate it V.,when my mind continually plays tricks with my brain.The voices I can live with,but when I start wandering to Venus and ordering meals I can't pay for.....

I have a large collection of mostly vintage amps, preamps and tuners. All have been completely dissambled, updated and restored to better than factory new. For instance I'm lucky to have an industrial pc board washer and a paint shop to put automotive finishes on my gear. I regularly swap components back and forth and the differences in sound quality are dramatic in some cases and barely audible in others. Minor bias adjustments have a huge impact on whether an amp sounds slightly bright or warm. I have yet to find an original, older amp (i.e. broken in) that had the correct bias setting either to factory spec. or set for lowest distortion. I have never been able to hear a difference between cables and feel certain that impedance and component matching have the biggest effect on why components sound different in different systems. As with almost everything else in life, maybe yes maybe no, depending upon many factors. Psycology definitely is a factor, as is the state of your sinuses and barometric pressure.