"The cafeteria was a complete madhouse" (Metaphor)
When Mr. Underwood announces that the boys are going to be doing a unit on wrestling in gym class, wrestling fever takes the school over. Greg uses the metaphor of a "madhouse" to illustrate just how crazy it felt to be in the cafeteria when everyone was wrestling with each other in anticipation of the unit in gym class. The "madhouse" metaphor captures the sense of chaos as well as the fact that the boys weren't acting like they normally should in school.
