Inspired by xkcd's thing explainer I generated a list of how often words appeared in subtitles on opensubtitles for my target language.
I whipped those into a database, added manual translation for the top-1000 and started quizzing myself with a tiny php script.
It was more fun to code than to actually quiz myself. I think I played the top-100 before I got bored.
Louis Theroux tried to make a documentary about them. He's done some really good work showing the worst groups in the world as, you know, actual human beings. Like the westboro baptist church.
The Scientologists refused to talk to him. Him talking to ex-members unleashed a stampede of harassment both against them and him.
The result is called "My Scientology movie". It's worth a watch if you're interested in their techniques to keep people from leaving.