could you pinpoint the moment you had that realization your prior beliefs were false?

Absolutely - you never forget something like that.

The issue/"knowledge" was good v. evil - the object of my attention was what eventually became knows as, "the religious right" (yes, I'm old and it was decades ago). Despite the "horrors" I'd seen and experienced, I'd never actually encountered anything I would have considered "evil", until then. If I was right, then they were evil and if they were right, then I was evil which I would not have had a problem with, except it didn't fit.

The point was, I was painting them with the same brush they were using to paint everybody that wasn't them. We were equals. Diametrically opposed, philosophically, but absolute equals.

The most awesome and rewarding adventure I've ever had. Everybody can't be right, obviously, but everybody can, absolutely, be wrong. And, as the exploration continued, I decided to use the idea that both sides of any argument are almost certainly wrong, as my base of operation. Hence, my personal mantra, "Reality isn't Wrong - Ever", which has always been there at the beginning of the very best explorations.