Ears like familiar sounds better than new sounds. You're probably getting used to the sound!

I think there’s only a very small amount of 'that' which goes on. I've fooled my minds ear a few times building something up in my head (too far) and when I go back to an actual source realizing I over/under emphasized. But if ‘getting use to the sound of a product’ had very much more than a negligible impact, I’d be surprised. Otherwise none of us could ever be capable of walking in a speaker demo room to upgrade our speakers to something that sounds vastly superior to the old speakers we are used to.

I do think with a pre-pro or receivers (with their varied array of functions and settings) that it takes time in each persons setup to overcome individual battles with room acoustics and the interactions of their different chain of components, - to get it where they like it. In other words, - optimization.