On Valentine's Day, SpongeBob is giving out Valentine's Day hearts to everyone. He even gives one to Plankton, which is delivered with the help of tweezers. SpongeBob goes to Sandy's Treedome where Sandy gives him an acorn nut with an arrow stuck through it which he chucks away. SpongeBob then takes out his bottle of Chocolate syrup and blows out a chocolate heart bubble for Sandy's Valentine. SpongeBob and Sandy then talk about what they have arranged to give Patrick for his Valentine Present, a hot air balloon made out of chocolate and how for everything to be arranged.
SpongeBob tells Patrick (who has made his Valentine's Present for SpongeBob by putting a big rock on the ground and pounds the rock into the shape of a heart, but smashes the rock into a pile of dirt thinking that SpongeBob is in there and then realizing that SpongeBob is behind him (said by SpongeBob) and give him a pile of dirt for his Valentine Present) that he has the best present ever ready for him. Patrick gets very blithe and impatient for his surprise present and the two go to the Valentine's Day carnival. Since it is a surprise present, Patrick starts to guess what is even to the point that he thinks it his present is a bunch of paramecium and to even the point that he thinks that his present is on top of Mount 'Climb Up and Fall Off' in which he runs up the mountain and falls off a couple times.
Meanwhile, Sandy, who is in route to the carnival in the chocolate balloon, is attacked by a flock of chocolate eating scallops, which causes the balloon to veer off course as she fights them off. Due to the delay, Sandy tells SpongeBob to take Patrick to the Ferris wheel to keep up his overexcited mood. SpongeBob starts to think that Patrick would not get his Valentine and doesn't want to break his heart so he takes him to the Ferris wheel to keep up his morale. When SpongeBob and Patrick reach the top of the Ferris wheel, they wait for the surprise to be revealed. However, Sandy contacts SpongeBob via his walkie-talkie, informing him of her troubles and since one of the scallops bit the balloon and the balloon is floating downwards that he will have to go with "Plan B." SpongeBob tells Patrick, who is so excited that he is literally shaken the entire Ferris wheel, that his present is a "friendly handshake". That greatly disappoints him and after shaking SpongeBob hand, he stares at his own hand with a grumpy look on his face. SpongeBob laughs nervously and throughout their playtime in the carnival, SpongeBob laughs at the joys of the carnival whilst Patrick has the same grumpy look on his face.
When Patrick and SpongeBob are sitting down at a table, he has been thinking and thanks SpongeBob for the gift he gave him, but when he sees many other people thanking SpongeBob for the gifts he gave them, including complete strangers (one man only asks for the time), he is pushed off the deep end and goes on a rampage. He begins destroying the carnival and corners everyone there, including SpongeBob, seemingly with the intention of killing them all. Before he gets the chance, however, Sandy arrives, having tamed the scallops, who is now helping to keep her balloon afloat. SpongeBob tells him that his true Valentine Present is behind him, but Patrick thinks that isn't true. Even with the help of the crowd persuading him to turn around, he doesn't turn around until Sandy says his name, in which he turns around seeing his great Valentine Present. Upon seeing this, Patrick takes a bite of his present in amazement, causing it to pop and covering the carnival in chocolate. Smiling at SpongeBob and completely forgetting his anger, Patrick joyfully says, "Aww, SpongeBob, you didn't have to get me anything!" as the episode ends.
Mr. Krabs and Gary the Snail do not appear at all in this episode, but all the other main characters make appearances or cameos.
There are 23 hearts on the title card.
This episode and "The Paper" only tend to air in reruns in the United States on or around Valentine's Day making this episode extremely rare and difficult to watch on TV, since they both aired on Valentine's Day, and are a Valentine's Day special.
In the Dutch version of this episode, when the guy asks Patrick for the time, Patrick actually tells him the time (3:15 PM) instead of saying "Patrick needs love, too!"
Patrick's quote "HEART ON STICK MUST DIE!" has become a famous Internet meme.
This also applies for Patrick's other quote: "I DEFY YOU, HEARTMAN!" which has also become a famous Internet meme.
When the scallops pop a hole in the balloon the first time, air is coming out, but when Patrick pops it a second time, chocolate sauce explodes out of it. But it is possible that it was a little air left. If there was not air in the balloon, it would not fly.
There is a game on the online game based on this episode this called Love Hurts!.
When Patrick throws the last male fish about to thank SpongeBob for his gift and Patrick becomes crazy, he bangs his stomach and acts like Kerchak from the Disney movie Tarzan, and the Marvel character The Incredible Hulk in both rage and speech.
When SpongeBob and Patrick are on the Ferris wheel, SpongeBob's shoes look like heels.
When Patrick goes on his rampage and the voice on the loudspeaker warns the crowd, the sound of an air raid siren can be heard during his rampage after the warning on the loudspeaker, it could be either for comedic effect or to also warn the crowd of Patrick.
In the original scenes with the "Valentine's Day Carnival" sign Mount Climb-up-and-Fall-off is not seen, but when Patrick mentions it, it can be seen.
When Sandy is on the chocolate balloon, her suit seems to be smaller.
When Sandy fights the Chocolate Eating Scallops, the balloon's basket seems to be missing, showing only the string attached to it.
While SpongeBob is delivering the valentines, at the beginning of this episode, the sky is pink; for the rest of the episode, the sky is blue. The pink sky may just be sunrise.
The rides at the carnival change place throughout the episode. For example, the "heart-on-stick" ride is to the right of the Ferris wheel at the beginning of the episode, but at the end when everyone is on the pier, the rides are still in the position it was at the beginning of the episode, even tough the pier is on the other side.
When Sandy opens her helmet to receive the chocolate bubble, no water comes inside her helmet, even though they are in water.
When SpongeBob is on the radio with Sandy, he says "You can bring it in now." However if she did, it would not be following his original plan of positioning Patrick on top of the Ferris wheel.