On Mel's trucker's cap is "W73". The W73 was a nuclear warhead for the American AGM-53 Condor missile.
Even though everyone blames George for hurting the Bubble Boy, during the confrontation where he is choking him, Susan can be seen hitting the plastic divider trying to help George. So in reality, it should be Susan who is blamed for the bubble boy getting hurt.
After Jerry takes Naomi home, he opens a bottle of water. At some point during their conversation we can see that the cork is on, then it's off when we cut to a reverse angle of the scene.
When Naomi calls Jerry's apartment to say she changed her mind about going to the cabin, Kramer answers the phone. Only problem is, he didn't pull out the antenna on the cordless phone so that he could answer Naomi's call. Jerry always makes a point of pulling out the antenna on the cordless phone before answering.
Elaine eats a broiled chicken in the diner in this episode when she previously stated that the only animal she'll eat is fish; I think it was the stranded episode
In order to win at Trivial Pursuit your token must be in the center. When the Bubble Boy asks George for the game winning question his token is clearly on the outside ring.
On the way to the bubble boy's house both Jerry and George's back car windows are blocked by luggage. Then after they are on the way to the cabin after they've reunited at the bubble boy's house, the windows are not blocked.
Kramer did not go to the cabin with either Jerry or George. Rather, he went with Naomi with directions that he found in Jerry's apartment. The only problem is that those directions were the ones given to Jerry from the bubble boy's father - to the bubble boy's house - and not to the cabin? How did Kramer find the cabin and then burn it down? He should have arrived at the bubble boy's house instead!
When Jerry confronts George of the message he left on his answering machine, in one shot, Jerry has his arms hanging down, but then in the next shot, he has his hands on his hips.
The set for the roadside diner Jerry and Elaine pull off at on the way to the Bubble Boy's house is the same set used for scenes at Reggie's Diner in later episodes.
Naomi: I thought you were happy-go-lucky.
Jerry: No, no, no, I'm not happy, I'm not lucky, and I don't go. If anything, I'm sad-stop-unlucky.
Jerry: He's a bubble boy.
George: A bubble boy?
Jerry: Yes, a bubble boy.
Susan: What's a bubble boy?
Jerry: He lives in a bubble.
Kramer: My Cubans!
(He runs off to the burning cabin)
(Jerry has lost track of George's car)
Jerry: What is he doing? Is he out of his mind? Do you see him? I don't even think I see him anymore. Where is he?
Elaine: Isn't that blue car him?
Jerry: No, no that's not him. What happened to him. I can't believe it. I lost him. That stupid idiot. Now what are we gonna do?
Elaine: It's no big deal, Jerry. We'll just meet him at the bubble boy's house.
Jerry: I don't even know where the bubble boy lives. I don't even remember the name of the town.
Elaine: You don't have the directions?
Jerry: No, I was following him.
Elaine: How could you not take the directions?
Jerry: Because HE'S my directions.
(George is driving too fast as Jerry is following him)
Jerry: What's he doing? What is his hurry?
Elaine: Well, you know George. It's not good enough to get there. You gotta make good timing.
Jerry: I know he once went from West 81st Street to Kennedy Airport in 25 minutes. I never heard the end of it.
(Elaine laughs quietly)
Jerry: Look at him.
Bubble Boy: What's your story?
Susan: I-I-I have no story.
George: She works for NBC.
Bubble Boy: How 'bout takin your top off.
Mrs. Sanger: Donald, behave yourself.
Bubble Boy: Come on.
Bubble Boy: Okay, "History", this is for the game. How ya doing over there? Not too good!
George: Alright Bubble Boy, let's just play. Who invaded Spain in the 8th century?
Bubble Boy: That's a joke… The Moors.
George: Ohhh no! I'm so sorry it's the Moops! The correct answer is the Moops!
Susan: So what kind of a bubble, like an igloo?
Jerry: No, that's what I thought. But apparently it's just a big piece of plastic, dividing the room.
George: What kind of plastic do you think it is? Like that dry cleaning plastic?
Jerry: That's no good. He wouldn't last 10 minutes in there!
Elaine: Well, what about the sleeping arrangements in the cabin?
Jerry: Well, um, same bed and uh, underwear and a tee shirt.
Elaine: What about me?
Jerry: You'll be naked, of course.
Elaine: What's that?
Jerry: Oh, it's an autographed picture for my dry cleaner. I don't know what to write on these things. I hate doin' this.
Elaine: (reading) "I'm very im-PRESSED?"
George: (voice on answering machine, about Naomi) All right, you know she's got that laugh. What did you say? It's like Elmer Fudd sitting on a juicer?
(Talking about George.)
Jerry: Look at him! he's going like a hundred miles an hour!"
Elaine: Yeah but it's not enough for George to go fast, he's gotta make good time.
Jerry: I know. He once made it from West 81st St. All the way to Kennedy Airport in 25 minutes, I never heard the end of it!
George: I'm sorry the card says "Moops."
Jerry: I can't date a girl with that kind of laugh...it's like CoCo Chanel goin' out with a Fishmonger!
(Talking about cigars.)
Kramer: These are Cubans. Maria, porquendo lociendo corendo congli!!
Bubble Boy: Moors!!