SpongeBob wakes up on a normal day, as usual. He looks out his window and sees the mailman riding by on his bike. He says "Hi" to the mailman. This causes the mailman to get distracted and a truck crashes into him. After that, SpongeBob wants to spend time with his friends; however, he ends up upsetting them: He accidentally breaks Gary's shell, crushes Patrick's cake, disturbs Squidward's beauty sleep, destroys Sandy's robot, and deep fries Mr. Krabs' money (and himself). SpongeBob decides to leave Bikini Bottom, as all his friends hate him (and cruelly call him "idiot boy"). As he leaves, he is scared by mysterious figures in the shadows. While he runs from the creatures, he falls off a cliff and bumps his head, and he gets a lump, and then his bundle hits him on his head knocking him unconscious. Back in Bikini Bottom, Patrick, who want to borrow some sauce for his milkshake, and Sandy find Gary who is huge and overweight and a note from SpongeBob, explaining that he has run away. They go to Mr. Krabs and Squidward who confirms that SpongeBob wrote this. Everybody is upset and guilty that SpongeBob is gone, with the obvious exception of Squidward, who is delighted.
Meanwhile, SpongeBob wakes up with amnesia. A couple of fish give him a new name, "CheeseHead BrownPants," so that they can steal his possessions and take advantage of his amnesia. All SpongeBob has left is a bottle of bubble soap. He wanders around until he ends up in New Kelp City where he attempts to get a job. Each time he gets a job he uses his bubble blowing ability to help him, but this strikes fear into all the residents of the city. This activity attracts the attention of the Bubble Poppin' Boys and their leader, Trevor, who have scared the city into never blowing bubbles ever again. SpongeBob uses his ability to get rid of the gang and is rewarded by getting the position of mayor of New Kelp City.
Back in Bikini Bottom, Mr. Krabs is hoping for the return of SpongeBob so he can prepare his station, while Patrick and Sandy want their friend back. Squidward didn't know until Mr. Krabs offers him a reward of a Fabergé egg. He chooses his love of art over his hatred of SpongeBob and the trio see a newspaper stand showing news of SpongeBob's position as mayor, but when they go to New Kelp City to retrieve him behind Squidward's back, he can't remember them. They then manage to kidnap SpongeBob and return him to The Krusty Krab, but he wants to return to New Kelp City. Squidward, who didn't know again if SpongeBob stays or not slips on a greasy spatula and accidentally throws his egg onto SpongeBob's head. The impact gives SpongeBob his memory back, and Mr. Krabs, Sandy, and Patrick apologize for running him out of town. But even so, SpongeBob still wants to return to his position as mayor, because he feels bubble blowing needs to be commonplace in New Kelp City society. At that moment a news report comes on the TV saying that the bubbles in New Kelp City are causing mayhem, and he is being threatened by a thug. Upon hearing this, SpongeBob has second thoughts about going back to New Kelp City and decides to stay in Bikini Bottom till he's dead. And then finally, Squidward opens his head and he throws his brain in a trash bin.
After Patrick says "Just a cake for my mom that I spent all day making, as he walks back into his rock, He turns around and looks back at SpongeBob and says "I'm gonna go back and make a 2nd birthday cake that my mother will like!"
After Sandy's robot breaks, Sandy shows SpongeBob it's broken head.
During the scene when the creepy people are scaring SpongeBob, a Scallop is shown crowing
After SpongeBob says "Ooh, boy! That's quite a lump!" Then he says "I better not hit my head again. That might cause a concussion."
After all the people run away from the bubble SpongeBob blew, he says "What could possibly be wrong with practicing the bubble arts? Seems like a harmless activity."
During SpongeBob's speech, he says "I can't say that I blame you."
Patrick and SpongeBob - "I'm gonna go back and make a 2nd b-day cake my mother will like!"
SpongeBob looking at Sandy's broken robot
"Get out of here!"
Mr. Krabs falling down
"I better not hit my head again. That might cause a concussion."
"What could possibly be wrong with practicing the bubble arts?"
Rather than the usual traditional SpongeBob SquarePants Theme Song playing at the beginning of the episode, instead the "SpongeBob SquarePants" parts have been altered to say: "WhoBob WhatPants."
Here are the things that SpongeBob did to get called "Idiot Boy:"
He accidentally destroyed Patrick's mom's birthday cake.
He disturbed Squidward's beauty sleep.
He tripped over and splashed water on Sandy's robot, thus destroying it.
He accidentally knocked Mr. Krabs' money into the fryer.
Sandy appeared to be either MIG or TIG welding. However, she had no protective clothes on except for her head shield (especially dangerous as she is covered in fur), and her gloves appeared to be rubber instead of rawhide.
In "New Digs," SpongeBob was one minute late and Mr. Krabs was okay with this. In this episode, he is not okay with SpongeBob being ten seconds late. He however, did say "don't do it again!"
Bikini Bottom's population is revealed to have been 538 (SpongeBob crosses out the "8" before leaving, so the population was 537 for the duration of this episode).
According to Patrick when Sandy was asking him where was SpongeBob, he said that he has been knocking on SpongeBob's door for 3 hours.
Mr. Krabs reads SpongeBob's note without an eyesight problem, but in "Greasy Buffoons," he reads with glasses on.
In "Texas," Sandy uses a handle to flush her tears out of her helmet. However, in this episode, she isn't seen using it.
The reason why Sandy didn't use the handle is because she was too upset to see SpongeBob leave forever.
Another reason why is because this time there weren't enough tears to completely fill up Sandy's helmet.
While walking in New Kelp City, SpongeBob asks an orange fish, "Is there something wrong with me?" After that, a hideous face of SpongeBob is shown, which has become an internet meme around YouTube. The fish is also the one who ordered the Monster Krabby Patty in the episode "All That Glitters."
After Squidward destroys the Sponge-Tracker, Mr. Krabs' nose swells up and explodes with a jet of water. Real-life crabs can do this, but instead, they squirt water from their eyes.
Squidward's hatred for SpongeBob is clearly demonstrated in this episode, as he attempts to sabotage the search efforts, to the point where Mr. Krabs has to bribe him.
Ray Liotta has been a voice actor three times before: the first time as, Tommy Vercetti, the protagonist of the video game Grand Theft Auto: Vice City; the second time as the lead Bubble Poppin' Boy in this episode; and the third time as himself in the 2007 animated film Bee Movie.