Jerry's poster presents the theme of the book in a simple way. At first, Jerry does not quite understand the poster, but he knows it appeals to him. It is only after he has begun refusing the chocolates and suffering the consequences that he realizes what it means to disturb the universe. Each time he opens his locker he is reminded of what he is doing, and of the fact that refusing the chocolates takes strength and bravery. The reader wants Jerry to abide by that poster, and one of the reasons the ending is so dismal is Jerry's realization that the poster is wrong—that one should not dare to disturb the universe because it simply is not worth physical damage to stand up for what you believe in.
The chocolates themselves are so insignificant that it is amazing to think that they began the whole, huge mess. The chocolates become a symbol for defiance and nonconformity, not just for Jerry but for the entire school. For a while, other students think that Jerry's refusal to sell the chocolates is simple and beautiful. Then the chocolates become symbolic of war—people believe that Jerry thinks he is too good to spend the time and energy selling them. The students rally around the chocolate cause in order to find a reason to be angry with Jerry and support The Vigils. The chocolates are the reason for the boxing match and ultimately solidify Archie's control over Jerry, Brother Leon and the rest of the school.
The collapse of Room nineteen is a harbinger for what is to come in the rest of the book. The Vigils make someone else take it apart and leave it just at the edge of falling down. Then, the rest of the students push it over the edge, tipping over chairs and desks, delighting in destroying a classroom. The students help the assignment come to fruition just as they help the boxing match and raffle come to fruition. The collapse of Room nineteen also signals the collapse of The Goober and Brother Eugene—two people that might have been strong allies for Jerry had The Vigils not taken them out first.