Has this ever happened to you?

it happened once and I pretended it didn't. Still chasing it (and what would I chase if I had it - scary prospect...)

LOL

This happens to me quite frequently. I'm really pleased with the sound of my system.

Yes, but it won't last long.

Yep, lol. This is the sad reality of most "hedonist" pursuits. Audio is less unhealthy than most others, at least :) 

Our subjective perceptions of sound are very powerful, but also quite inconsistent, ever-evolving, and influenced by a zillion factors outside our control. My "better" systems have had far less "off days". When I've had a system that wasn't quite right, the delta between "good" and "bad" days was crazy. Some will attribute this to variable power quality, EMI / RFI levels etc. Not here - I think the biological soup inside my skin bag is to blame lol.

Congratulations. 

I can't say this has happened to me exactly that way. But once I have gone through an upgrade cycle... my attention turns from the system to the music and there is typically a big sigh of relief and an appreciation of the music that my new system creates. Then, I forget about the system for five to ten years and just enjoy the music. So, I guess the answer is, yes.