If it's my mood, then typically, I'll end up playing multiple disc's without feeling gratified by any of them... and end up switching off the system.
Sometimes the system sounds especially good and I tend to assume it's associated with power, although I could be wrong.
Of course, if there's actually a problem like sibilance, which, as it happens, I've so far failed to solve, listening will just trigger frustration. My workaround is limiting my listening to instrumental music.