Apparently, the end of the series St. Elsewhere revealed that the entire show was in the mind of an autistic child named Tommy Westphall. Although I remember watching the show, I think I had checked out of television watching by the time the show finally ended. And yes, while that's an interesting ending, nothing will probably ever, ever beat the end of Newhart.
Anyway, there's nothing that we respect more around here than people who are bigger, more effective geeks than we are. Notice the use of the words "more effective." And we think it's pretty darn effective when you decide to postulate that a great portion of television all exists with Tommy's mind due to all the guest starring bits and crossovers between various shows. It's like a television version of Wold Newton, for crying out loud.
Get the full skinnee, along with the full diagram and explanation, here.