I've been through numerous similar "mysterious" experiences like the ones that Curtis described, ever since my awakening as an audiomusicophile in my high school years (in mid/late '70s). Early on, I had once even wrapped my speaker cables with aluminum foil after reading somewhere about the wonderful effects of such treatments -- and actually heard the difference! I also tried a good number of different "seating materials" on my Denon turntable -- and I thought I heard an improvement. I swear that each and every one of my own such experience was REAL when it happened. However, to my disappointment, NONE of them was reliably reproducible later; I did not even need to blind myself to re-test them with negative results (yes, I was aware of the concept of blind testing already in the '70s, even before going to college).
Fast forward two decades, after moving to Texas and initially settled on the Adcom 200W/325Wx2 power amp that I still use, I brought in home a number of "high-end" amps from dealers and friends in order to seek for a better sounding amp. In several occasions, I did hear a clear improvement with a new amp, which obviously made me very excited. However, again, EVERY one of these "improvements" was later found out to be so unreliable, much to my own dismay -- one day, I thought I heard the difference, the next day, I wouldn't... In the end, I was never able to convince myself into investing additional $$$ (not an insignificant amount, btw) in any of these amps. Again, I never even tried to blind myself, or set up a true instantaneous A/B comparison. I simply relied on my own ears, manually swapping the amps... Mind you, I wasn't doing these tedious in-home tests in order to "prove" that these high-end amps were no better than my Adcom. Rather, I was eagerly willing to buy one of those if I was convinced that they provide a definitive sonic improvement. I was disappointed in the end...
So, Curtis (and others), the practical $0.02 I have here is that a one-time experience may have very little significance in the end. Don't try to convince yourself just yet, based on those "chance observations." Rather, first try to see if the phenomenon reliably repeats itself again and again, on different times and occasions, irrespective of time of the day, astrological alignments, and your own mood. You should go from there...
