Do your ears deceive you?

Of course your ears can deceive you. Your mind can play tricks on what you "want to hear" as opposed to what is really being played. This will largely depend on your age and hearing, but no question about your mind playing tricks on what you "want" to hear.

On a side note, I have not changed any of the power cords nor I have spent extra $$ for speaker cables or interconnect upgrades. In case you are wondering, here is what I have:

Speaker cables: Kimber 8TC Kimber Kable 8TC Speaker Cable Review

Interconnects: Wireworld Equinox III Wireworld Equinox III+ interconnect & speaker cable

 We don't typically listen under blind conditions.  If an improvement is perceived, and it is unshakable under normal listening conditions, then it works for you. We need not ask why - unless we're curious about it. When people start giving untested and unlikely explanations for why, that's when people rightfully start questioning, and that's when the ones making the claim needs to prove their explanation in a rigorous manner. 

asctim

... When people start giving untested and unlikely explanations for why, that's when people rightfully start questioning, and that's when the ones making the claim needs to prove their explanation in a rigorous manner. 

Nonsense. This isn't a scientific forum. No one here owes you any "rigorous" explanation or any other kind of proof, although of course you're free to conduct your own experiments and share the results. If the empirical evidence described by users here is insufficient for you, perhaps you are in the wrong place.

We don't typically listen under blind conditions.  If an improvement is perceived, and it is unshakable under normal listening conditions, then it works for you.

So you'd be ok owning expensive cables if you knew that if you were blindfolded you couldn't discern a difference between them and inexpensive cables? That would be ok because when you could see the cables (normal listening conditions) they sound better? I know the answer is that you wouldn't know that because you wouldn't test that. I figure that's the reason most cable lovers bend over backwards to justify not testing their sighted conclusions.

Long ago a friend went crazy over a couple speakers designed by a Professor of Engineering.  The Prof claimed to have found the magic enclosure dimensions and configuration for flat 20-20K response from a single 4 inch driver.  Also claimed a perfect stereo image regardless of placement.  The friend was dead serious believing the claims.  Actually sounded like what you would expect from a 4 inch driver in an enclosure about the size of 2 cigar boxes.

In another discussion a person referenced a speaker cable blind test conducted by "experts" as proof blind tests are the only valid method to identify if differences exist.  Two cables at very different price points were evaluated.  Listeners heard a difference.  Therefore because it was a blind test the results must be valid and statistically significant.  Only problem, 3 music tracks, 3 listeners, 2 cables of large cost disparity.  A poorly constructed test that proved nothing.     

The tendency to believe those with knowledge, authority, or the badge of "expert" is very strong.  Those factors contribute heavily to individually held bias.