Funny how such threads always ending in people discussing subtleties in, and reasons for something that's never proven in the first case.... It's like medieval philosophers discussing how many angels could sit on a needle's point....
Myself, I hear considerable differences in my hi-fi systems, depending on my mood.
Fortunately, I know too much about psychology as well as physics, to waste my time discussing which parts of my hi-fi set up that might cause these differences.