He doesn't really seem to be the type to just decide to mentally check out - being how cerebral of a pitcher he is. I thought I read that he voiced dealing with some injuries most of last year, which probably contributed - but it could have been a multitude of factors.
Regardless, this year he seems to be right back to where he left off in 2018 - at least to this point.
Pretty wild that the Reds have possible front-runners for both NL Cy Young AND NL MVP on their team, yet still have struggled mightily as a collective. If the other guys can just play to even 80-90% of the levels that their history dictates, then I could see a huge win streak coming. Fingers crossed.