Have you ever hated the sound of your system one day, and loved it the next?

Last night I went to bed thinking my system was going down the tubes. This morning I loved it.
 Last night it sounded painfully bright and unbalanced.  This morning, on the same CDs, it sounded full and rich.
Now, I ask you, is it the system or me???
  I understand changes in electrical currents from the wall can play a part, but I have an expensive power conditioner.
 I was just wondering if this is a typical bugaboo among audiophiles.
The flaw in the logic here is the expensive power conditioner.  They can definitely improve some things, but cannot eliminate all the variations provided by your local friendly (?) utilities company.  Beyond changes in your own metabolism/mood, this is definitely what you're picking up.
Most systems always sound best in the morning and late evening. Especially Sunday morning. Less RF interference. Most systems also sound best on nice sunny days and worst on rainy low pressure days.
I've noticed same things as geoffkait.  Moved here to Phoenix area 8 months ago from Detroit area.  Used to have "good" and "bad" days with my system in Detroit.  Great sounding one night, bad the next day.  Haven't had any changes like that here, though.  Fingers crossed, I think we have a great electric system!

I’m glad for these posts.  I see it’s a common phenomenon.
 The difference is LITERALLY night and day!