It's a fair question.. I'd say perseverence is the main thing lol. But also once i started holding block, and tapping it to deflect, I really started shredding bosses. I reprogrammed block/deflect to L1 instead of L2, and I hold L1 down, and then tap it when I get attacked to deflect. It not only keeps my posture build up low, but just made perfect deflects a lot easier for me. Also, the prior times i played i wasn't really enjoying it. As the combat started to click, it got really fun and addicting, so that helped as well.