Fan theories from Croke Park to Westworld

This is quite the feature in the modern age, the extent to which fans of a TV series/movie/song/gif deconstruct same and produce complex explanations for the machinations they’ve seen.
The ease with which those theories can be promoted and shared tends to give them legs: my own favourite revolves around the notion that all the Pixar movies take place within the same universe, making Andy’s mother in Toy Story the little girl who loses Lots-o’-Huggin’ Bear early on in Toy Story 3 (or is it Jessie in number two? Answers on a postcard, etc).