Looking back from almost 40 years later, it’s hard to believe that the TV show Mork & Mindy only ran for four years. It left a permanent impression on the world because it was Robin William’s first starring role. Therefore, people who weren’t yet born when the series ended in 1982 are familiar with it, but probably don’t know much about what went on behind the scenes. For example,
1. THE SHOW WAS INSPIRED BY AN EPISODE OF THE DICK VAN DYKE SHOW.
You’ve probably heard that Mork & Mindy was a spinoff of an alien character on Happy Days, and that’s true. But the Happy Days character was inspired by an episode of The Dick Van Dyke Show called “It May Look Like a Walnut,” which featured an alien played by Danny Thomas. When Dick Van Dyke director Jerry Paris was later hired to direct some Happy Days episodes, producer Garry Marshall mentioned that his Star Wars-obsessed young son wanted to see a spaceman on TV. Paris remembered the success of "Walnut," and Mork's extraterrestrial encounter with the Cunningham clan was created. The episode “My Favorite Orkan” was such a hit that it received its own spinoff: Mork & Mindy.
4. PAM DAWBER DIDN'T REALIZE SHE HAD BEEN CAST.
Pam Dawber had a development deal with ABC where they paid to keep her under contract until they found a project for her or the contract expired. She filmed one pilot called Sister Terri that flopped: "I played a nun who used to be a gang leader but she found God, so she's there to fix up the neighborhood," Dawber explained. It didn't sell, but scenes she filmed for it were later spliced with scenes of Robin Williams from his appearance on Happy Days. The cobbled-together example did the trick, and Mork & Mindy was sold without so much as a pilot. Dawber found out about it when her agent discovered a write-up of the show in Variety. "I hadn't auditioned, I hadn't met, and I knew nothing," Dawber said. "I remember going, 'And who in the hell is Robin Williams?'"
There’s plenty more to learn about Mork & Mindy in a trivia list at mental_floss.