- Squidward Tentacles
- Patrick Star
- SpongeBob SquarePants
- Frank the whale
- Andy Yellowtail
- Martha (mentioned)
- Fish on Simple-Ton (cameo) (debut)
- Incidental 39
- Gary the Snail (cameo)
- Sandy Cheeks
- Bubble Patrick (debut)
- Larry the Lobster
- Frank (store owner) (cameo)
At the Krusty Krab, SpongeBob and Patrick are making their favorite noises, while simultaneously annoying Squidward. SpongeBob's is the dolphin laughing and Patrick's is the song of the great blue whale. Squidward, who is extremely annoyed at this point, asks them what was happening. They explain that they are doing stuff together out of a magazine called Simple-Ton. They then take a quiz to find out how much they know about each other and SpongeBob does fantastic. However, Patrick does terribly.
Patrick buys two ice cream cones (but only gets his favorite flavor, which is dill pickle swirl with mustard and extra bacon bits) and asks SpongeBob for money. SpongeBob becomes upset, and he tells Patrick that he doesn't know him anymore after tearfully throwing the money on the ground. He then runs off to his house, crying. Eventually, SpongeBob goes to Sandy for some advice. She says that SpongeBob and Patrick don't have to know everything about each other and probably just need some time apart.
SpongeBob then tries to avoid Patrick, but he sees him go to the gym and many other places with Larry. Patrick is shown with a gift when SpongeBob angrily confronts the two, followed with Larry uncomfortably backing away from them. Patrick then explains that Larry is not his best friend and that Larry helped Patrick find a gift for SpongeBob, which is a pair of glasses with a fake nose and mustache. SpongeBob and Patrick become friends again until Patrick gets scared by SpongeBob in the glasses and runs away, with SpongeBob quietly sighing "Why me?"
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• Aloha Bikini Bottom - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Title card]
• Gator - Steve Belfer [SpongeBob and Patrick making noises]
• Steel Licks 3 - Jeremy Wakefield ["Didn't think so."]
• Soap Opera Scene 2 - Hiram Titus ["Huh? Did you hear that?"]
• Unknown Goofy Cue - Nicolas Carr, Barry Anthony [Simple-Ton magazine]
• Light Conversation 1 - Nicolas Carr, Barry Anthony [Best friend quiz]
• Lap Steel - Nicolas Carr [Patrick's belly button]
• Steel Licks 22 - Jeremy Wakefield [Squidward walks away]
• Tip Toe Through the Seaweed - Nicolas Carr, Barry Anthony [SpongeBob quizzes Patrick]
• Gametime - Nicolas Carr, Barry Anthony [Jeopardy-style music]
• Hello Blues - Sage Guyton, Jeremy Wakefield ["So, who won your stupid quiz?"]
• Popcycles and Ice Cream - Nicolas Carr [ice cream truck]
• Steel Licks 3 - Jeremy Wakefield [Patrick asks SpongeBob for five bucks]
‣ Fates [#62] - Gregor F. Narholz ["Here! Take your dirty, rotten money!"]
• Aloha Lui Lui - Nicolas Carr, Sage Guyton, Jeremy Wakefield [SpongeBob crying in bed]
• Who Said That - Nicolas Carr, Barry Anthony ["Hey there, SpongeBob!"]
• Steel Licks 1 - Jeremy Wakefield [SpongeBob at Sandy's treedome]
• Steel Licks 8 - Jeremy Wakefield [SpongeBob leaving Sandy's treedome]
‣ Hawaiian Party - Peter Dennis ["I don't need Patrick! I can have a good time all by myself!"]
• Noodly Shenanigans - Nicolas Carr, Barry Anthony [SpongeBob hides underground]
• Steel Licks 9 - Jeremy Wakefield ["He doesn't seem to be missing me at all."]
• Sneaky Panther Pants - Nicolas Carr [SpongeBob spying on Patrick]
‣ Dramatic Impact (6) - Ivor Slaney ["To tell me about your new best friend Larry, I suppose?"]
• Steel Licks 26 - Jeremy Wakefield [Larry backs away]
‣ Pua Paoakalani B - Kapono Beamer, Queen Lili'uokalani [Patrick explains]
• Puka A - Sage Guyton, Jeremy Wakefield [Ending]
- This episode is available on the Complete Seventh Season, SpongeBob SquarePants Vol. 12, The SpongeBob SquarePants Collection, Gary Falls in Love, Bikini Bottom Buddies, The SpongeBob SquarePants 8 Season DVD Collection, Next 100 Episodes, and The Best 200 Episodes Ever DVDs.
- "You Don't Know Sponge" was ranked #44 during the SpongeBob's Top 100 event in the UK and Ireland from June 4-8, 2012.
- There was a 3-hour marathon about friendship leading up to the premiere of this episode.
- There are 15 jellyfish on the title card.
- However, they have no spots like in "Tea at the Treedome" and are a darker shade of pink.
- In British airings of this episode, the scene where Patrick turns on the blender that SpongeBob is hiding in is cut due to violence. When Patrick approaches the blender, it cuts straight to the magic shop.
- In this episode, SpongeBob is ambidextrous, but in "I Was a Teenage Gary," he says he is left-handed. In "Neptune's Spatula," he has two left hands. In "The Splinter," he also says that he is ambidextrous.
- Though, an explanation for this is that SpongeBob can regrow his appendages like real sponges.
- In this episode, Patrick is right-handed. However, in "The Camping Episode," Patrick is shown writing with his left hand.
- This could hint Patrick is ambidextrous.
- This is one of the few times when Patrick interacts with Larry.
- This is the second time Patrick is shown singing "Leedle leedle leedle lee!" The first was in "Shanghaied."
- This is the second appearance of the Magic Shop, but this episode is the first time the interior is seen. The first appearance was in "F.U.N."
- Frank, the owner of the Palace of Pranks from "Pranks a Lot," appears again, this time working at the Magic Shop.
- Coincidentally, there are two Franks in this episode, the first one being Frank the Whale and the second being Frank the store owner.
- There's an episode of The Looney Tunes Show called "Best Friends" that is outwardly similar to this one. In the aforementioned episode, Bugs Bunny and Daffy Duck take a quiz about each other, similar to how SpongeBob and Patrick did. Daffy didn't know anything about Bugs, similar to how Patrick didn't know anything about SpongeBob.
- It's revealed that SpongeBob's favorite color is beige, his favorite food is Krabby Patties, he has an outie belly button, and his favourite ice cream flavor is plain vanilla. However, in "Sold!," SpongeBob said that his favorite food is actually Kerglooginpfiefer.
- It is also revealed that Patrick has an innie belly button, his favorite color is aquamarine, and his favorite ice cream flavor is a dill pickle swirl with mustard and extra bacon bits.
- This is the second episode where Patrick thinks SpongeBob is a stranger due to SpongeBob wearing something. The first is in "To SquarePants or Not to SquarePants."
- This episode reveals that Patrick knows nothing about SpongeBob despite being his best friend, not even the most simple things about him.
- However, this may simply be due to Patrick's low intellect rather than negligence.
- Starting with this episode, every episode usage of the production music track "Gator" is in a lower pitch with exceptions of "New Fish in Town," "Patnocchio," and the second movie.
- When SpongeBob gives Patrick the $5, he throws four bills and four coins on the ground, then cries like crazy. This means that he probably gave Patrick four $1 bills and four quarter coins.
- Squidward is briefly seen reading the Fancy Living Digest magazine from "Chocolate with Nuts" at the beginning of this episode.
- Patrick's favorite flavor of ice cream is dill pickle swirl with mustard & extra bacon bits, however, he ends up buying it for SpongeBob and purchases the plain vanilla ice cream for himself.
- Only four APM tracks are played due to the heavy usage of original music playing throughout.
- The episode title is a pun on the video game series, You Don't Know Jack.
- The magazine Simple-Ton is a play on the word "simpleton," which refers to a very foolish and gullible individual.
- While Larry is at Cooking Supplies, in the first shot, his shorts are green, but in the next shot, they are black.
- When SpongeBob says "Now, now, Patrick may not have passed the quiz, but like a true best friend, he's always right here, for me, right Patrick?" and looks at the latter, his legs are missing.
- SpongeBob reveals he has an outie belly button, but most of the times when he is shown naked, it's not there.