This page lists fan theories about the television series SpongeBob SquarePants.
The Seven Deadly Sins Theory
Although the theory was debunked by SpongeBob's voice actor (Tom Kenny) in this HuffPost interview, it is possible that SpongeBob's friends represent the Seven Deadly Sins. There is some debate, but the best fits for each sin are as follows:
It has been suggested that Patrick or Gary could also fit gluttony, since Patrick also loves eating a lot of food. Gary's food bowl is commonly seen, and the episode "Have You Seen This Snail?" features him running away after not being fed, but he is not fat like Mrs. Puff or Patrick. Also, his appetite is perfectly normal for a snail. Some fans think SpongeBob could fit lust since he is so loving, but he has been confirmed by Nickelodeon to represent positivity and optimism (opposites of sin), making it unlikely that he represents one of the seven sins. Additionally, his love for the world is genuine, not sexual.
Nuclear Testing Theory
SpongeBob SquarePants takes place in Bikini Bottom, a fictional undersea community located underneath a real-life isle called Bikini Atoll. Back in 1946, Bikini Atoll was used by the United States as a site for nuclear testing. Numerous bombs were set off there over the years; a particularly notable one called "Baker" was detonated 27 meters underwater. See Wikipedia's article on the island for more information. This theory states that SpongeBob and his friends are all so bizarre because they are the results of these nuclear tests.
Donut of Shame/The Secret Box Connection
Below is a summary that connects the events of "The Secret Box" with "The Donut of Shame."
Patrick's birthday is near Christmas. SpongeBob set up a tea party for Patrick. When Patrick was at his birthday party, SpongeBob invited tons of friends until SpongeBob brought out a bottle of grog. Patrick and all the other guests chanted at SpongeBob to drink the entire bottle. SpongeBob started to feel dizzy. He danced on his table and prank called everyone else he knew. Patrick, unaware that his best friend was drunk, decided to take a photo of this moment. SpongeBob felt so dizzy that he said "A donut this nice could really make a guy happy!" before passing out. Patrick ordered another bottle of grog and drank the entire bottle just like his best friend and passed out on SpongeBob's kitchen ceiling. Later on, Patrick put the photo of SpongeBob in a box he calls "The Secret Box".
The Drug Theory
This theory states that five of the characters are each addicted to a different drug. There are several versions of this theory, popularized after a parody called "SpongeBong HempPants" was created.
This theory also states that Sandy is against the others. As most viewers know, Sandy can get very annoyed when SpongeBob and Patrick visit her...because they are hyped up on drugs.
The Death Theory
This theory is a possible explanation for what many fans perceive as a negative change in SpongeBob's personality from the fourth season onwards. He is initially an intelligent and capable character who is rather naive, but he becomes increasingly stupid as the show progresses. This theory suggests that the old SpongeBob died during the 2004 film's famous death scene. Since sponges can asexually reproduce babies that are like clones, it is quite possible that SpongeBob was replaced by a baby of his, which is why SpongeBob's personality changes and why he never seems to age. It also explains why he is increasingly stupid: he is a child. But this was later to be disproved by Stephen Hillenburg who stated that season 4- present are all prequel episodes to the first 3 seasons and the first movie the 2nd movie is also a prequel. This explains why there are no mentions of SpongeBob ever being manager or what happened after the first film.