Sorry if we're still appearing hostile. We have a very focused target audience -- people doing mathematical research -- and in order to serve that community bes

Sorry if we're still appearing hostile. We have a very focused target audience -- people doing mathematical research -- and in order to serve that community best we turn away questions at inappropriate levels (i.e. what should be 'standard material' of a mathematics undergraduate education at a good university). We try to do that politely, and offer suggestions of other places to try, but I know we don't always succeed.