Remembering what I had done wasn’t something I liked to think about. Knowing you weren’t half as good a man as you thought you were was rough. I’d crossed a line I thought I wouldn’t cross. And I had to live with that knowledge.
But this kind of self knowledge is very valuable. Knowing the extent of one's capability for harmful, evil behaviour allows one to recognize its beginnings and halt it before doing harm -- when one wishes to do so -- there are circumstances where giving free reign to one's destructive impulses is an appropriate response.