Over the course of many years, my wife and I, who are pretty much a traditional couple, have given about 20 dinners a year for various friends and acquaintances. Good drinks, good food, good wine, and everybody seems to have a good time. Occasionally we receive "thank you" notes. However, many of our guests rarely or never reciprocate. If they don't reciprocate after accepting three or four of our invitations, they go "off the list." If they don't like us, I would much rather that they didn't accept the second or third invitation. We don't expect much in the way of a fancy dinner from them -- pizza, Chinese take out, anything would be fine ; it's the thought and the occasion that counts. Nor do we expect one-for-one invitations. But every once in a while would be nice. So, what's going on? Do others have the same experience? Thanks for any comments . . .