Norm struggles to remember his wife Vera's maiden name, though in Two Faces Of Norm, he remembered the name (Kreitzer) well enough to use as an alias.
When Cliff quizzes Norm's memory by asking who played the Bad Guy in Herbie The Love Bug, Norm answers Keenan Wynn, which was accepted as a correct response. In the original Herbie movie, titled simply The Love Bug, the Bad Guy was played by David Tomlinson, Keenan Wynn played the Bad Guy in the sequel Herbie Rides Again.
At around 15 mins., Frasier is visible through the window of Cheers' front door; he appears to be standing waiting for his cue, even looking through the window as if gauging when to go on. The next minute, he enters carrying his jacket and his son Frederick as if he has just arrived. It is possible that he was waiting to enter for some other reason, but he looks more like an actor waiting for his cue.
Frederick's line of dialogue when he delivers the bowl of pretzels to Norm was both unintelligible and clearly overdubbed.