On Valentine's Day, SpongeBob is giving out Valentine's Day hearts. He even gives one to Plankton, which is delivered with the help of tweezers. SpongeBob and Sandy have arranged to give Patrick a hot air balloon made out of chocolate. SpongeBob tells Patrick that he has the best present ever for him, and the two go to the Valentine's Day carnival, with Patrick extremely excited for his surprise present. Meanwhile, Sandy, who is in route to the carnival in the chocolate balloon, is attacked by a flock of scallops, which causes the balloon to veer off course as she fights them off. When SpongeBob and Patrick reach the top of the Ferris wheel, where the surprise is to be revealed. However, Sandy contacts SpongeBob via walkie-talkie, informing him of her troubles and telling him that he will have to go with "Plan B". SpongeBob tells Patrick, who is so excited that he is literally shaking the entire Ferris wheel, that his present is a "friendly handshake", greatly disappointing him and making him very angry.
When Patrick sees many other people, including complete strangers (one man only asks for the time), thanking SpongeBob for his gifts to them, 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 are now helping to keep her balloon afloat. Upon seeing this, Patrick takes a bite of his present, 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."
This episode and "The Paper" only tend to air in the United States on or around Valentine's Day making this episode extremely rare and difficult to watch, 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!!"
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 wasn't air in the balloon, it wouldn't fly.
This is the first episode to feature Plankton without having a scheme to steal the Krabby Patty Secret Formula (Sleepy Time doesn't count because it was some time at the night).
There is a game on the SpongeBob website based after this called Love Hurts!.
When Patrick threw that guy and became crazy, he banged his stomach and acting 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 looked like heels.
When SpongeBob is on the radio to 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.
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 is can be seen.
When Sandy is on the chocolate balloon, her suit seems to be smaller.
When Sandy fights the 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 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.