Being self-aware requires logic. No human being who isn't uh objectively damaged is incapable of discerning the fact that their existence and/or pain is distinct from that of others. Let me put it to you another way: If there is such a thing as "wrong", what could be more wrong than killing a whole lot of people simply because your life hasn't met your expectations for the same? I mean, damn. To paraphrase Walter Sobchak..."Say what you will about the tenets of National Socialism, Dude....at least it's an ideology."
In our world, yes. Who knows what's truly going on in a world of someone like that, and no two are likely the same.
Or I could even be completely off base with that, because my own logic like that might not even apply.