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.
The faster you go, the more students you leave behind. It doesn't matter how much or how fast you teach. The true measure is how much students have learned.
I imagine one of the reasons people cling to their hates so stubbornly is because they sense, once hate is gone, they will be forced to deal with pain.