People are fascinated by evil because it's mysterious and it doesn't seem to have a rationale behind it, and the second you say that Hannibal Lector was abducted as a child and he had to eat his sister or something like that, it becomes immediately mundane. The character becomes mundane.
“Twinkle, twinkle little bat How I wonder what you're at! Up above the world you fly, Like a tea-tray in the sky.”
“After every storm the sun will smile; for every problem there is a solution, and the soul's indefeasible duty is to be of good cheer.”