Cantilenam eandem canis

To be always singing the same tune, or telling the same stories, which, though at the first they might be interesting and pleasant, at length become, by repetition, tiresome and disgusting. Dieu nous garde d'un homme qui n'a qu'une affaire; God keep us, the French say, from a man who is only acquainted with one subject, on which he is capable of conversing; he will introduce it on all occasions, though it have no affinity to the subject which the company are discussing. He will lug it in by the neck and shoulders.