Claim: In "Bobby Goes Nuts," Bobby never enrolled in any martial-arts-related classes.
Evidence: Unfortunately for Bobby, when he goes to the Y to sign up for boxing, he finds out the class is full. Bobby asks to be enrolled in something, and is placed into a self-defense class for women because it is the only thing that is open. After some initial reluctance from the instructor, Bobby is allowed to stay in the class and quickly learns and masters the technique taught as self-defense: a hard kick to the testicles, usually preceded by a yell of "That's my purse, I don't know you!"