I Think what BFit247 meant was a joke, hence his "LOL." In documentary Bigger, Stronger, Faster, Greg Valentino made a sarcastic joke about Arnold and saying "You think it was all God given genetics" in his best Arnold voice haha.
If that's not what he meant by it, then it was just a coincidence.
I had the same problem, still do a little bit, but its no where near as bad. I used a machine seated press machine that has a slight decline on the seat. I too dont feel muscle pain from decline bench. This seated press I can load up and feel the pain. Works well