I grew up in an abusive household and, like many such kids, gravitated toward abusive people in adulthood. I've never been naive about sadists and sociopaths.
But I don't think our psyches were built for the never-ending assault of how persistent the need for cruelty is for some people, and how pervasive it is.
I know "the cruelty is the point" is nothing new. But I was unprepared for just how many people unapologetically feel that way. That I no longer see them as outliers is soul-crushing.