Well maybe it IS my hearing

Some would look like a donut.

Everyone hears differently. Literally, differently. On a cellular level even. Haven't seen the genetics on hearing but the studies on taste and vision show genuine differences in perception that are grounded in biology. This is in addition to things like physical deterioration with age, trauma, etc.

This still leaves a whole lotta stuff people are able physically to hear, yet will not know or report that they heard until and unless they develop the ability or skill to do so. Which definitely includes the vocabulary necessary to describe what you're hearing. My view is there's a lot of this. In other words regardless of how bad you think your hearing is there's a lot more you can hear than you think. But like with any sport you just need to work on your technique.

For example- long ago I was sure there was no difference between cables and CD players. Several times I tried and could hear no difference, even between things as obviously different as my old Magnavox CDB-650 and a ten times as expensive (and helluva lot newer) Wadia. One time I even was there when a guy who had made an appointment came in to compare two very expensive CD players. Wadia or Proceed and Levinson, something like that. Stood right behind the guy, and he took his time, never saying a word until the end he says hate to say this but I'm not hearing any difference.

Ha! See! Its not just me! Its all a scam! This guy sees it now too!

Except, one thing kept bugging me. I just couldn't shake this feeling there was something different, and I really was hearing it, only I couldn't quite put my finger on it. 

The idea there were people who could hear stuff I could not, this frustrated the hell out of me. Absolutely had to get to the bottom of it.

And it took months- MONTHS! - until one day listening to of all things an XLO test CD track - at home, on my crap JBL lamp cord stereo- I had this epiphany. Eureka! I had finally begun to put my finger on a few of the sonic attributes that distinguished the sound of one component from another. And things went very fast from there.

By very fast I mean it only took another few months of this time dragging my wife around to see if she heard these things too, followed by a few more YEARS of driving around, home auditioning, reading, reading, reading, listening, listening, listening.

Which if a few years seems not very fast well it looks that way from 30 years later.

Probably two of those years I was active in audiophile clubs and by active I mean probably visited 30-50 homes, never passively listening either but always with a few components or tweaks to compare in their systems.

So while these are all listening skills I believe anyone can learn and that will enable anyone and everyone to hear all the crazy things people talk about, I also try and keep some perspective on just how long and hard they may need to devote themselves in order to do so.

It ain't easy. Sorry if I ever gave anyone a hard time acting like it is. 

I wholeheartedly agree with your post. 

In regards to the topic of hearing, mine is limited to about 12kHz.  

I have a lot of aftermarket power cords and interconnects, but I have never experienced a single instance where there's been a noticeable before and after difference when I've done these "upgrades". 

There have been a couple of instances where I used some cheap cables and could tell they didn't sound very good and were not letting all the music through.  I did notice an improvement after taking them out of the system, but I don't usually discern differences between good and better cables.

I've sat through a couple of demonstrations of replacing interconnects and digital cables where someone else quickly made the change and I could detect noticeable differences in those situations.  

I have never done that kind of quick swapping with my own equipment and perhaps if I did, I would notice the difference. 

I take more of a "do no harm" approach and buy cables that are "better" (better construction, better connectors, better materials, better shielding, etc.) than the stock cables, but I don't really consider them to be "upgrades" because I can't tell much difference if any to my listening experience after I do it. 

I can hear significant differences between amps, preamps, speakers, cartridges, DACs, CD players, etc. which leads me to question if the cable "upgrades" are real at all, or if it's that what's left of my hearing just isn't good enough to detect those more subtle changes.

I have no way of knowing if others hear a more significant difference than I do.  When I read professional reviews where they review a number of different interconnects within a manufacturers line and detail the differences they hear from one to the next, I'm always impressed by their descriptions, but wonder why I can't detect those differences.

I don't question others spending more than I'm willing to on certain aspects of their equipment if it helps them reach whatever goals they have for their system.  First of all, it's really none of my business and their hearing may be more acute than mine.  It may make a more substantial difference in sound quality to them than it does to me.

I tend to dismiss posters that are always speaking in absolutes, whether it's that one approach to bass management is the "best", or that certain brands are the "best", or that some components either have no effect or have a huge dramatic effect and that you're either wasting money or that the rest of your system is crap because you didn't spend enough money on _____. 

It's not just our aural perception, but it's also taste and perspective.  One person may really enjoy a system that I find compromised and someone else might find the system I enjoy to be underwhelming.  My system sounds amazing to me until I hear someone else's that does _________ better than mine does, and once I hear that difference, I can't help but notice how my system is lacking in that aspect.

I think the key is to use your own brain and your own ears and use both to filter out all of the various opinions expressed on forums like these and find the best way to enjoy the hobby for yourself based on your budget, hearing, and taste.