Is it all in my head??

At this point, I'm ambivalent about cables and power cords.  I keep hoping to hear a change in my system if I swap cables or power cords, but I'm never quite sure I hear anything different in the sound.  I don't have an inexpensive system, and have cables and power cords from Purist Audio, Shunyata, Tara Labs, and at least three other companies.   But, unfortunately, I really never hear a difference.  Yet, I persist in trying things in hopes that I may hear something different and, to that end, just ordered balanced XLR cables to connect the pre-amp and amp in hopes I might hear a change.  

To your question - if you hear a difference, even if it is because of confirmation bias - does that matter?  Apparently, you think something has changed.  If it makes the music you're listening to "better" in some way - enjoy the difference.

I wonder why people with an opposing opinions are quickly labeled as trolls. Also, people who hear a "big difference" in the sound of cables, always ignore simple tests when it comes to choosing cable a from b. Any test that supports hearing the difference in sound, becomes invalid because it's a test. 

Vodka? They have tests for that, too:

https://www.npr.org/templates/transcript/transcript.php?storyId=588345420

I guess there are sepratate definitions for scitentists and subjectivists for a reason.

If you can't pick it out with the lights out, it doesn't mater if your a scientist or "open minded" and driven by  subjectivity. It is the same result at a different cost.