My chemistry teacher was passionate and seemed over qualified and I think that made him sort of come across as bitter at times. He didn't always understand why other people weren't as passionate. Anyways, I heard he had got sick and left teaching. But about a year or so later he was all over the news as he was apparently making really pure meth at a macro level for a cartel and had somehow ended up with some biker gang and was found dead. Crazy story.