Now in the final show of St. Elsewhere, it is revealed that the entire show took place in the mind of Tommy Westphall, the autistic son of one of the show's doctors. In essence, it was a dream.
Then someone noticed something amazing: characters from St. Elsewhere had appeared on Homicide. Detective John Munch of Homicide has appeared on the X-Files and most of the Law and Order series.
As St. Elsewhere became the Kevin Bacon of TV series, there's a good chance your favorite show is also a figment of Tommy Westphall's imagination, up to and including Dick Van Dyke and the Andy Griffith show, which took place before St. Elsewhere.
This happened because Cheers crossed over with Caroline in the City, which crossed over with Mad About You, which crossed over with both Dick Van Dyke and Andy Griffith.
And of course, if one wants to include the Simpsons, then Tommy Westphall encompasses virtually every TV that has ever existed.
See how fun this is?
I don't know why, but I love this idea more than words can express.