About a year ago I went to a public lecture at a public library about lighthouses. I was really looking forward to it, but it turned out to be rather dull. It started out okay. I learned some new things about lighthouses, but it descended into a slide show of a lighthouses around the country with the same type information being given about each (height, location, etc.). What made the whole thing worse was the "lighthouse people" who were in the audience. If the speaker made some sort or mistake about the size of a lighthouse, or if he left out any information the lighthouse people felt was important they would either snicker, or yell out. It was incredibly obnoxious. They were lighthouse know-it-alls. I run into know-it-all any time I go on a tour or to a lecture. Their questions are usually not really questions but rather a 5 minute speech of their own which only serves to proove how much they know about the topic. At the end they might ask "what do you think of that"?
When Jacobs goes on a New York Historical Society museum tour and runs into a rival know-it-all with whom he competes to answer any of the tour guides questions I am reminded of all of the times I have endured listening to people like that. Jacobs ends his description of this encounter with "I'm troubled: am I as annoying to the rest of the world as this guy is to me?" The answer, A.J., is quite simply, yes.