Changing audio beliefs

I used to believe cables and power conditioning etc did not matter.  Then I built a fully treated properly calibrated studio with full treatment (clouds, diffusers, giant first reflections, giant chunk bass traps in a properly sized room with 10’ ceilings) and reluctantly did some demos with a local hifi store owner.

Biggest surprise was USB cabling making a significant difference.  All 1s and 0s right?  Come visit my studio and you will hear every single cable change.  Interconnects are very subtle to me but otherwise they are subtle to minor to pretty significant with each change.  Proper power conditioning was the other thing (Gemini 8 from Shunyata and also tried a Hydra Sigma that was even better) Shunyata and Cardas made a super skeptic into a believer.

I just spent some time trying to think of something that’s changed in my musical beliefs and I really can’t. I have always been open to trying new things and ideas. 
My musical tastes have changed a bit. I still don’t like hard Rap, hard Country and Opera, but now I’m listening to more Jazz than Rock.

Are beliefs not for fairies and Santa Claus? Surely, in audio it is matter of taking a considered view on the basis of experience. When it first appeared, I found CD unlistenable. Then by the late nineties, I’d heard CD players that weren’t so unpleasant. After a decade or so of CD being the main source, ripping them seemed to produce better results. After that, I heard turntable components that made vinyl a wonderful listen. More recently, I have found ways of improving streaming. So over the decades my views have changed considerably, but belief doesn’t come into it. It’s just a matter of what I can achieve with the equipment I have.