People with lousy (nonexistent) listening skills love to crack jokes. The differences some of these things make are beyond easy to hear. One time I came home to a new IC and with little time between shifts raced to hook it up right out of the box. It was a used cable, should have been broken in, sounded absolutely horrible. Not imperfect, not disappointing, not bad. Horrible. Awful. Bad enough I lost sleep that night wondering what might have gone wrong.
The next day at work it dawned on me, I didn't recall checking direction. That night first thing sure enough it was backwards. Switched around and warmed up it still needed a few hours to settle in but now it sounded really good.
These things do happen. They do make a difference. Just not a difference everyone is able to hear. That much at least is clear.