I need helps explaining this?

Okay, so my dad REALLY gets under my skin because I know a lot of facts about Vlad the impaler, Hitler, Mary Tutor, and many other people who were in power in history and considered evil. He says that I have a twisted mind because, according to him, no normal person would want to know things like that. But I don't know how to explain that I'm not crazy or dark, I'm just fascinated by this stuff, not unlike how criminal profilers are fascinated by the mind of criminals. Can you help me come up with a reasonable explanation for why. I'm not entirely sure why I am fascinated with this stuff - im not crazy, and i don't want to hurt anyone ever, i just find it interesting.