At Goo Lagoon, Plankton arrives to turn the beach into the future site of the "Chum BucketMega Bucket," and demands everyone to leave the beach. However, due to his tiny size and small voice nobody pays attention to him. He concludes that he needs someone big to help clear the sea creatures of the beach for him, and encounters SpongeBob. Plankton decides to trick SpongeBob into being "assertive" in order to get the things that he wants.
SpongeBob tries to buy ice cream, but gets cut off once and then has his ice cream stolen. He once again tries to buy and ice cream but learns that there are no more left. He notices Plankton crying nearby and asks him what's wrong. Plankton says that he bought a second ice cream that he doesn't need, and he doesn't have anybody to give it to. SpongeBob offers to eat the ice cream. Afterwards, Plankton offers to teach SpongeBob how to be assertive. He tries to get SpongeBob to take his ice cream back from the person who stole it, but SpongeBob's kindly nature prevents him from being able to take it. Plankton, unhappy with SpongeBob's performance, climbs into SpongeBob's mouth and uses his words to forcefully take the ice cream. He attempts to have SpongeBob forcefully take back his metal detector that he lent to another beach-goer, yet SpongeBob misinterprets Plankton's instructions and the person he lent the detector to is pointed out buried treasure by SpongeBob.
By this point, Plankton decides to give up, but SpongeBob promises to prove to him his ability to be assertive. Plankton allows SpongeBob another chance. SpongeBob commits a series of both assertive and antagonistic acts to beach-goers, including stealing the hotdogs of characters in line to buy them and cutting the strings of people's kites, and everybody leaves the beach.
Plankton then reveals his true intentions to SpongeBob, making him very upset. SpongeBob defeats Plankton by becoming "aggressively nice", and he undoes the actions that led to the people leaving the beach. Plankton leaves the beach due to the overwhelmingly generous acts of kindness that SpongeBob executed.
Several production images suggest that this was originally intended to have the episode production code, "16b." However, it's actually ended up being "18b."
When Plankton is putting things in his suitcase, he puts in a shirt that looks like Charlie Brown's, except it has a red zig-zag.
SpongeBob's stand-up routine is patterned after Jerry Seinfeld ("What's the deal with...?").
When SpongeBob is being "assertively nice," he gives out five kites. At the end of the episode there are only four.
After Scooter rode with SpongeBob (who was shaped as a surf board) his pants are green. Though when Plankton is seen moping away in public Scooter's pants suddenly turned purple.
After SpongeBob cleans the girl's ice cream, it is still dirty in a later shot.
SpongeBob's tan permanently disappears after just one shot with it.
When Fred gets sand in his eye, it is unknown why he says "MY LEG!"
There are six kids lined up at the hotdog bar, and the octopus gives each a hotdog. When SpongeBob extends his tongue, there are only four kids there. The camera cuts back to the bar, and five kids are seen leaving.