Continuity mistake: Frasier is at Cafe Nervosa and tears off the edge of a sugar packet which he leaves on the table. Subsequent shots sometimes show the paper there, and sometimes not.
Continuity mistake: When Frasier is talking to Patrick Stewart (who is putting his coat on) in Cafe Nervosa, the collar on Patrick's coat fixes itself between shots, without him doing anything to it. In particular, one of the lapels is stuck under the coat for one shot and is suddenly normal in the next shot.
Continuity mistake: When Frasier prepares to leave the gay bar, he puts his sherry glass on the bar and pulls back - but the next shot shows him pulling back from the bar again.
Continuity mistake: After Gil comes into Frasier's booth to talk following the 'outing' caller, Frasier begins packing his briefcase, then shuts it. Seconds later, it is still open and he shuts it again.
Answer: Nanny G (Nanette Guzman - played by Laurie Metcaf) has been a children's entertainer for twenty years, and tells Frasier, "Do you know what it's like to play the same character for 20 years?!" The joke is that Kelsey Grammer has been playing Frasier Crane since 1984, when the character first appeared on "Cheers", so Kelsey in real life has been doing just that!
Super Grover ★