More to Joseph O'Neill's story than initially meets the eye

Read Joseph O'Neill's story The Trusted Traveler in Harper's - readers of Netherland alrady know that O'Neill can be a great writer in the long form; this was the first story of his that I read. Story is well-paced and clear and mysterious, and seems to mean more for me on reflection than it did first time through. Story narrated by a mid-60s h.s. teacher who has retired and moved, with wife, Chris, also a teacher I think, from Manhattan home base to the coast of Nova Scotia. The eponymous traveler is a 30-something man who claims to be one of the narrator's former students and who has visited them pretty much annually for the past 10 years right around tax time (the former student is an accountant, we learn in one passing reference). The kick is that the narrator and his wife do not like these visits, and in fact he cannot even remember that this younger man was one of his students. They try politely to dissuade him, but he's annoyingly persistent, and shows up for a visit - with wife, also named Chris, not along w/ him - and he later lets out that they are separated. Another couple joins, some awkward conversation over dinner, he leaves the next morning, time passes, and the next year the couple surprisingly realize that tax season has passed and they have not heard from the former student. Is he well? alive? what happened? End of story. Easy to stop right there are think, OK, so what - but I have thought more about the story and think there are some nearly hidden mysterious elements. For one thing, the couple have this little game they play in which they create an imaginary life - the time we spent in Corfu, for example - one will say, and the other has to pick up the strand. So we suspect that the traveler is someone whom they have mutually fabricated (much as George and Martha do in Who's Afraid of V Woolf? - a married couples game with delineated rules). And then we think: are the narrator and his wife "imagined" characters as well, imagined by O'Neill and in a sense by all readers of the story? And for that matter, to what extent are our friends, especially our distant friends and acquaintances, "real," especially in this age of FB and social media when we "friend" people we hardly know or don't know at all - and then "communicate" with them more than we do w/ people whom we really know, even our family? So this small story is seemingly simple but strangely provocative.