Revealing mistake: In "Not Normal" when SpongeBob says "Hmm. This video tape should help," his left arm is missing. (00:01:25)
SpongeBob SquarePants (1999)
1 revealing mistake in season 6 - chronological order
Starring: Clancy Brown, Tom Kenny, Bill Fagerbakke, Rodger Bumpass
Best Day Ever/The Gift of Gum - S4-E20
Revealing mistake: When Squidward says "I suppose if you haven't fixed my clarinet, the concert would have been a bust", Sandy's tail is the same color as her suit.
Spongebob's Last Stand - S7-E22
Mr. Krabs: Alright, Plankton! It's Eugene Krabs, here, with, What's-His-Name! Now come on out!
Plankton: I can't.
Mr. Krabs: Come on outside, and take what's coming to you!
Plankton: I really can't come outside!
SpongeBob: Why not?
Plankton: Because I'm already out here, you bumbling bottom feeders! Open your eyes for crying out loud!
Driven to Tears/Rule of Dumb - S4-E17
Question: Exactly how did Patrick get his licence when he can't even remember his own parents half the time?
Answer: I think that this was supposed to be an intended joke. Patrick is too stupid to remember or achieve most things and SpongeBob is able to remember and achieve most things, but the one thing that SpongeBob cannot achieve, is the one thing Patrick can achieve on the first go.
Casual Person