A Teachable Moment

Malini found a new PBS program for the kids to watch - "Sid the science kid." As the name suggests, they try to impart some basic science info. What I didn't bargain for (maybe the name of the main character should have alerted me) was the "jokes" that the show included. They run sort of along the following lines:
"How do you stop a fish from smelling?"
"I don't know. How?"
(This is the only acceptable response, you aren't allowed to guess.)
"You hold its nose."
(You have to hold your nose while saying this, which imparts the necessary nasal tone.)

Arjun was quite taken by this new game (maybe something in his genes as well) and Abhi was too, except that he didn't quite grasp the notion of a punch line, specifically that each joke has its own punch line. A couple of days ago I came home to this question:
Arjun: "What did one shirt say to another shirt?"
Me: "I don't know. What?" (I wasn't just playing along, I really had no clue.)
Arjun: "Nothing! Shirts can't talk, silly!"
(Me, grimacing, but trying to be a sport.)

Apparently there was a follow-up:
Arjun: "Why did one shirt chase the other shirt?"
Me: "I don't know. Why?"
Arjun:"Because they were playing tag!" Hillarious stuff.

Abhi certainly thought so, but he was a little confused about the two different jokes and ended up combining the question of the first one ("What did one shirt say to the other shirt?") with the second punch line ("Because they were playing tag."). Not just that, he started applying it to everything around the house. For instance:
Abhi: "Aeta, What did one banana say to the other banana?"
('Aeta' or more correctly, 'Cheta' is Malayalam for elder brother.)
Arjun (playing along): "I don't know. What?"
Abhi (in a triumphant voice): "Because they were playing tag!"

Now, this was sort of ok the first 10-15 times, but after that even Arjun gave up and tried to explain to Abhi that the two jokes were different. ("Abhi, in the first one, they are talking, not playing tag.") When that failed, he attempted an illustration:
Arjun:"See, I'll show you. What did one Sid-the-science-kid say to the other Sid-the-science-kid?"
(He was picking somebody who would actually talk.)
Abhi (being well-versed in the protocol of this joke): "I don't know. What?"
Arjun (talking directly at Abhi): "Hello, Sid, how do you do? What are you doing, Sid?"
Not much of a punch line, but hey, it was supposed to be an example. Instead, Abhi, who by now has lost all context interjected rather emphatically:
"I am not Sid, I am Abhi!"