I think this may be a case of "damned if you do..." as I very much dislike the opposite. I don't want authors talking down to me. I don't want them to explain every little thing. If there's something integral to the plot that I don't understand, I find it a lot less aggravating to look it up than when the opposite occurs and an author explains something I'm already familiar with.
edit: Or what DiapDealer said.