You mentioned that, “What I really wanted from quitting my job was not a new one, but to know why he did it and stop the torture of innocent souls who deserved more.” Not sure that you achieved this or that it was even achievable. The guy will still be a bully, because it is what he understands and what works, most of the time. Not bringing this up to HR just gives permission for the behavior to continue. Not that HR will respond immediately, but they do take notice when they receive reports of repeated bullying or abusive behavior. And if they don’t, then each person needs to decide for themselves what they are willing to tolerate, because it is likely to be a lousy work culture. The fact is, not everyone experiences that behavior to the same degree or in the same way. I saw various forms of intimidation and bullying behavior where I worked, but it was seldom directed at me. However, when I was directly subjected to micro-managing controlling behavior, not as bad as bullying, to be sure, I took the opportunity to leave.