I don't know why I'm telling you this, perhaps I'm hoping it will go away.
I have recurring nightmares, about three things. I used to have only one, but it went away. I had a bedroom (I didn't really, it was in the nightmare) which was three floors up in a house and I had to go through a winding corridor to get to it, but I kept getting stuck in the corridor and died. Most nights.
I'm glad I don't have that one any more.
The ones I have now are from experiences.
First one: I was a Plod at the Guildford Bombings (yes, I am that old) and I had to pick up bits of body and stuff. I get flashbacks from that one, still. I think this was in 1976.
Second one: I visited an old gaol somewhere in the lakes years ago. There was a dungeon, which was a gurt hole in the ground, with a small hole into which they dropped a prisoner for (say) stealing a chicken or owing the council some money. A "magistrate" sentenced him to having his arms tied behind his back and then dropping him down the hole, so his shoulders dislocated. If it didn't work, they did it again with weights tied to his feet, and if it didn't work again, increased the weight until it did. I think they did this in the 1800's.
Third one is the story of a chap who had a cross-amputation, i.e. have one arm and the opposite leg removed, with no anaesthetic, on a carpet of polythene, by "priests" with bonesaws and butchers' cleavers. The thing that got me was that he said "please make it quick." They didn't. They did this very recently and a far as I know they still do.
What I'm getting at is how, and why, a human can do any of these things to another human, or animal, in the name of some old bollocks which really didn't matter then and still doesn't.
WHY can't people just be?
"Many and sharp the num'rous ills
Inwoven with our frame!
More pointed still we make ourselves,
Regret, remorse, and shame!
And man, whose heav'n-erected face
The smiles of love adorn, -
Man's inhumanity to man
Makes countless thousands mourn!