Things I Have Learnt number 53: There are some questions you should never ask in a social setting. Like "How old are you?" or "Did you make the pastry as well?" or "Is that because you is mental?" We know not to ask these questions. Others are less obvious. For example, don't ask, "Are evil spirits self-maximising?" It's facetious.
Am reading Maryse Condé's Moi, Tituba, sorcière... Noire de Salem.