I do NOT refuse to accept the validity of blind testing equipment, cables or tweaks.
That's good.
However, I am unable to do blind testing. So, I rely on my hearing.
Ok, that's fine. As I've argued, most of us don't have the time or set up or inclination to do blind testing. Buy what you want, for whatever reason.
But it gives me plenty of reason to maintain skepticism if you happen to make claims for hearing things that are technically improbable. My skepticism shouldn't stop you from buying whatever you want of course...but if for instance you said an expensive digital cable made Big Differences in your system vs a functioning cheap digital cable, I'm quite aware it is likely sighted bias at work, unless it could be shown you or someone else could reliably identify these changes "without peeking." ;-)
Not too bad in my opinion. I also listen to my friends who have superior acoustic listening/interpretation ability. They pinpoint problems, one who has Asperger and audio sound is his superiority in life. His hearing is like a computer. I don't inform my two Golden Ear friends what I have done/doing. They tell me what they are hearing and often, what corrections should be made. Try topping that with Blind Testing by the usual crowd of audiophiles. They have really taught me to hear/listen better. My wife is so used to decades of my cable testing for the manufacturer that she automatically is skeptical of the sound whether it meets with her approval or something less. She said I have trained her to hear sound as well as music. Before me, she was fine listening to a boombox and car radio.
And the point that you don't want to acknowledge is that literally nothing you described in that paragraph protects you or anyone you mentioned from regular old perceptual biases in which you can hear things that aren't there.
Maybe that sounds dismissive to you. But think of what your position will be when I might say "I don't hear a difference" with some gear change that you believe sounds different. Your response will be dismissive of my hearing (or gear, or whatever), it won't act as any evidence against what you firmly believe because, as you've said, if you believe you heard it, it's true.
And, once again, I tend to buy gear essentially the same way you do, by listening to it, so we are not that far off as audiophiles. I just try to maintain epistemic humility in the face of our perceptual fallibility, and acknowledge I could be wrong.