Variations in how your system sounds?

Apologies if this has been covered elsewhere.
My system sounds consistently good to my ears for the majority of listening sessions but every now and again (say 1 in 20) it sounds slightly 'off' -- not its usual self. It is a very small difference but i do hear it. I would describe it as a slight lack of focus and dynamics. This has happened through many changes of all components.
Is it my mood, or hearing variation? Do i need to filter my power? Do you have similar experiences?
I've used that ear wax removal stuff (ear drops then you douche with water) for years (musician) and it is kinda amazing, and for me completely necessary.
If one cleans their records one would hope that one would also clean ones ears in order to hear better as well as for hygiene reasons, right? It can and does make a difference.

Now to start the marketing campaign for "Earcleaners for Audiophiles"...... :-)
'I DO NOT can playing a digital track on a system demagnetize it? This will be added to the 12,416 things I don't understand, unless somebody can explain it to me.'

Does the term 'MONEY' ring a bell? Actually the disc works on the same principle as 'hospital grade' outlets.
Rok2id: The disc was free, so along with your inability to explain how a disc can demagnetize my system you rendered your entire response irrellevant.

I replaced the cheap $1 outlet for my system with a PS Audio Power Port. That's something I DO understand.
'Wolf_garcia: The disc was free'

And just how was I supposed to know that? :)