Accidental Innuendo: Squidward playing a clarinet-shaped SpongeBob. A clarinet is a woodwind instrument.If you don't get it... Squidward blew him.
Franchise Original Sin: This could be the first episode classified as "SpongeBob annoys everyone around him". Unlike later episodes at least, SpongeBob's antics in the characters' dreams don't lead to anyone getting seriously injured or the like, and don't come from sheer stupidity but rather just general curiosity of others' dreams.
In the ending, Squidward asks SpongeBob, "Don't we get enough of you during the day?" "Gone" reveals that Bikini Bottom has a holiday devoted to avoiding SpongeBob.
SpongeBob upstages Squidward in his own dream. "Choir Boys" turns his dream into a reality.
Informed Wrongness: While Sandy, Squidward, Mr. Krabs, and Plankton have valid reason to be annoyed with SpongeBob for ruining their dreams, SpongeBob did nothing to warrant anger from Gary and Pearl. Pearl's dream he simply entered by accident and she even invited him to stay; Gary's dream was simply reading poetry to SpongeBob and he caused no problems. Gary did scold SpongeBob for "invading the sanctity of his dream" when he first saw him in his dream, though, so it could be Gary found him entering the dream wrong in and of itself.
Heartwarming Moments: When Plankton, in his dream, menaces Bikini Bottom, SpongeBob only intervenes when he sees that Gary is right in his path. Any pet owner would do the same.
Memetic Mutation: "Why have you stopped playing that wonderful music?" And SpongeBob shriek-singing beforehand.
Crosses the Line Twice: Patrick putting SpongeBob on a medieval torture rack, complete with darkened torch-lit room and Patrick wearing an executioner mask (keep in mind, Patrick is doing this in the belief it would help SpongeBob get better).
Fridge Horror: What would have happened if SpongeBob hadn't been taken to the hospital?
Franchise Original Sin: Patrick's idiocy harming those around him really starts to show up in this episode. Unlike later episodes though, it's from projecting his own fear of the doctor onto SpongeBob and genuinely wanting to help him get better, instead of coming from legitimate stupidity that ends up being actively malicious to those around him. He's also punished appropriately instead of being treated as an Idiot Houdini.
Harsher in Hindsight: The "sponge treatment" scene becomes this in "Model Sponge" when SpongeBob is forced to clean a bathroom for a commercial, and this time he's not happy about it.
Karmic Overkill: Some fans feel that Patrick's "special treatment" where he's maimed and humiliated is a bit too harsh of a punishment, as while he did impersonate a doctor, he was ultimately trying to help SpongeBob get better, with SpongeBob's expressed permission. Readers of the book adaptation, SpongeBob Goes to the Doctor, feel that Patrick's punishment of being forced to read old magazines is much more fair, as it not only serves to be a Cool and Unusual Punishment that only Patrick would be scared of, but also serves as a Bookend to a Brick Joke.
SpongeBob, big time. He accidentally falls asleep in front of his open fridge, gets horribly sick, is sent home early from work against his will, and is physically, but unintentionally mistreated by Patrick, who persuades him, through "scary" stories, that doctors are evil. It's a good thing he's better at the end of the episode.
Patrick as well. His best friend ends up horribly ill, leaving him horrified. He genuinely is afraid of doctors and believes he's helping SpongeBob (which SpongeBob asked him to do), yet ends up painfully punished for something that wasn't even malicious.
", is a song In the Style of The Beatles. In essence, the audience is experiencing Beatlemania for SpongeBob.