What you guys are missing here is that sometimes the suggestion that something has changed is enough for you to perceive a change even if one wasn't made. No one is immune to this. Not you, not me, not Jauqo, not Bob Clearmountain, etc. I've seen it in action a million times with plenty of folks with excellent ears.
This phenomenon does not in any way diminish one's ability to discern very fine real changes in sound. Like I said earlier in the thread, I could reliably detect the difference a slightly out-of-tolerance resistor made in an electronic crossover I designed. However, I will freely admit that in that same amp, I fooled myself into hearing changes I made in a part of the circuit that I forgot I had bypassed (so changing resistors had no effect). I eventually figured it out but it took a while. I've done monitors for artists who asked for a little more this or that when the whole system was at the edge of going ballistically unstable and heard an improvement by me pretending to turn a knob.
The other factor to consider is that environmental conditions can affect sound quite a lot especially when very subtle changes are involved. A little air current here, not having your head exactly in the same position there, etc. all affect your perception of sound.
Again, I'm not casting aspersions on your or Jauqo's or anyone else's hearing and listening abilities at all, but to deny the possibility that sometimes your auditory perception can be affected by psychology is just silly.