One of the phenomena that I find particularly interesting is the way that people create canons in their head that are based on existing intellectual properties but are not official and confirmed by those who create those properties. It is common these days for creative people to combine their creativity into the same universe. So it is, for example, that we have a Marvel Cinematic Universe that contains a huge number of films, whose popularity is helped by the fact that the movies have built in fans who want to see how each individual character fits into the larger universe and in films with other characters. When it is done well, it offers a compelling example of worldbuilding. It is not always done well. When someone does the extended universe in their head, it is called headcanon, and it can often lead to interesting results.
Let us take, for example, the television shows of one Dan Schneider. Dan Schneider was, for many years, a successful showrunner for Nickelodeon, and in that role he produced numerous successful shows for the network, many of which that featured a small group of actors and actresses who played in show after show. As one might imagine when someone was responsible to making numerous shows for the same network, there were crossover episodes that combined some of those shows together. So, for example, an episode of iCarly featured the cast of Victorious as part of it, and a later show paired one of the characters from each of those shows, and still other shows made reference to or shared a universe with other shows of his, even though some actors played multiple roles within different shows, all of which leads to questions about the role that some shows play in others and that some characters play to their obvious dopplegangers.
Sometimes, as is the case in the example I just mentioned, headcanon helps us sort out some of the inconsistencies that exist in universes that have been sloppily put together by others. So, for example, some people think that the show Drake & Josh is in fact a reality television show, even though the show itself contains numerous actors and at least one character who appear on other shows within the Schneiderverse. At other times, though, headcanon can help create new works by putting together the independent works of an author together. So, for example, one may assume in one’s headcanon that all of the Jane Austen novels are part of the same shared universe even though this indication is not given, all of which allows the possibility, for example, that some of the characters might be able to interact with each other and perhaps even be friends with each other. One could ponder, for example, on the thoughts of the naval party of the Crawfords with the naval party of the Crofts and Wentworths, with their very different moral standards despite their similar profession, or one might ponder what it was like when Sir Thomas Bertram discuss matters in Parliament with Mr. Darcy, or to see Mr. Gardiner engage in trade with the Mr. Coles of the world.
This too may be headcanon, and a great many stories may be created through the imagination of the interaction of other characters who have already been well-described and plotted out by another. Whether Jane Austen would have created novels where previously written characters interacted with each other or whether further events in the lives of her popularity characters would have been delineated is, unfortunately, not something we have the chance to know for sure, for Jane Austen’s novels were only released over a period of a few years while she was in her late 30’s and early 40’s, with two novels being published after her death, with at least two more substantial novels never being finished at all in the Watsons and Sanditon, both of which and numerous other stories which would have further showed her growth as a writer and her sensitivity to the changing conditions of her time. In the two centuries since her death, though, Austen’s own novels have been combined together as part of a shared universe in the headcanon of a great many readers, myself included. Who would not rejoice in an Elinor Ferrars being friends with an Anne Wentworth, or Elizabeth Darcy being a guide to many a future generation of young woman whether in London or at Pemberley? Let such pleasant thoughts animate us in adding to the greatness of works by placing them together in a shared universe where they may interact with each other.