I always thought that the writers couldn't figure out a way to make Robin Williams fit into "Happy Days" so they just created something that did work for him.
My favorite meme about "Mork and Mindy" was that Boulder was the perfect place for the show since the rest of the population of Colorado thought that everyone in Boulder got there by spaceship anyway....
...and that was before the real nutburgers got to town.
Ever do the Halloween Mall Crawl in Boulder? Wowzers