I think you're actually having a quite profound insight into a truth about human nature. We are all, each one of us, probably capable of evil way beyond what we would care to acknowlege. Fortunately, we may never have to face up to just how bad we could be. We may never be in a set of circumstances that tests us beyond our ability to manage.

It's been found that, in circumstances of war, for instance, very ordinary people with seemingly normal, decent values can find themselves committing atrocities. The main difference between those people and the rest if us may be largely a matter of most of us having the good luck to never find ourselves in an extreme situation. I think it can be a mark of moral and psychological maturity to gain some grasp of this truth and let go of some of our smug assurance that we are nice people who could never do anything really all that wrong. We could do a lot worse than we think we can.