Component Break In. Truth or Fantasy

Suspensions that flex like speakers and phono cantilevers definitely benefit from some working time,  Caps seem to benefit from playing time as well.  It's harder for me to be sure about wire.  Sometimes it's just a matter of getting familiar with something and recognizing subtleties.  

I have fifty years of experience. Virtually all components have breaking. I broke in three identical Audio Research amps, each had the same very specific behavior over 600 hours. Around 120 hours after very notable improvements the sound quality would vary flipping back and forth between really good and bad. I can describe the specific behavior of different preamps.  The Audio Research Reference 5 series has a very unique warm up sequence. The Reference 6 has nearly none.
 

Hearing breaking requires listening skill and a resolving system. Some people don’t have the skill, interest or system.

"Hearing breaking requires listening skill and a resolving system." +1

"Some people don’t have the skill, interest or system." and these are the ones teaching others that it is all imaginary and delusional.

If one does not hear something, it does not mean that it does not exist.

Everything matters. 

In one respect, it doesn't really matter, you put a new component in your system and play it-whatever happens will happen. Whether it "breaks in" or not is utterly beyond our control.

I have a resolving system and I have a fair amount of experience, and my hearing is slightly above average for a 68 year old, and I've never noticed any dramatic changes-if others do its not for me to argue with what they hear-how could I know and why should I care?

On the other hand, its a bit disingenuous, to say the least, to suggest something on the order of "we should all trust our ears, but if you don't hear exactly what I hear, your ears or your system are not to be trusted" That's a bit of a debating trick to advance dogma that can't be proven or disproven.

It makes sense (at least to me) that mechanical devices might have a "break in" period and I've noticed that, but nothing dramatic. I think science tells us that expectation bias is real and that, over time, our brains accommodate to changes in the sound brought on by new components. I've noticed that subjectivists-of which I am one-often simply ignore these seemingly well-established occurrences, perhaps because they are inconsistent with our belief system concerning this stuff. For me, I suspect that's part of it-but maybe somehow electronic components do "break in" and maybe the sound almost always improves as it changes, which seems odd, but certainly possible, I suppose. 

I have an open mind on break in. Less willing to accept. the assertion that anyone who has not heard dramatic differences as new components age means their ears or their system is somehow primitive compared to those who perceive something different. 

I think I'll trust my ears.