How often is your system "good"?


In a recent article in Stereophile, the author wrote, "When my system is good, it forces me to appreciate artists and songs I'd never noticed before."
http://www.stereophile.com/content/schiit-audio-yggdrasil-da-processor-page-2#bQow2O0DxgbPdplw.99

My presumption is that the author meant that his system sounds better some days than it does others.   I think this is an accepted fact.  I believe my system does better early in the morning and late at night due to power constraints.  I have a voltage meter on one of my outlets and I feel better about the sound when the voltage isn't sagging.  

My question for readers here is how often is your system good?   And to what do you attribute the goodness of your system from one day to the next? 
mward
  My system sounds best after an hour or so of music.  When I first turn it on it can sound a little thin and brittle but after that it sounds great.
My system sounds best:

Early Saturday mornings.
After 20 mins of warm-up.
Playing a class A sound quality album.
With no one else in the room.
Even with a dedicated line, still sounds better with no washer/dryer/dishwasher/timers/fluorescent lights/blow-dryer/oven on.
After a glass of wine. And then another...

Tom
I'll be honest, unfortunately my system hasn't reached the point yet of being able to notice a big difference when the quality of my supplied electricity varies...working on it though. As others have said, I really enjoy music when I'm alone and can really just melt into the couch with nothing to distract me. When I can sit back with a nice beer or bourbon and maybe a puff or two and can totally forget about everything but the music, that is when I find I most enjoy my system.