[bigmonkey]

We had a class last year in philosophy called Normativity, the study of norms. A norm is something that you should do. Some may have heard the distinction between a subject (for example ethics) being normative or descriptive, concerned with what we ought to do and what we actually do. We'd had this class for ten weeks and in the last lecture the professor asks the class what a norm is. A guy I know to be quite intelligent and one of the better students insta-calls the question with "something that usually happens", dead seriously.
Professor not best pleased.