Infinite Jest is notoriously difficult to read and follow, in part because it is an encyclopedic novel. It has a central fictional narrative, but it also explains and represents a massive array of scientific and cultural knowledge through footnotes and digressions. This genre stretches back to works like Herman Melville's Moby-Dick, which teaches readers more than they ever wanted to know about the whaling industry while also telling a compelling story about people within that industry. Postmodern novels like Infinite Jest take this encyclopedic approach to the extreme as they try to convey a sense of how complicated the world is—there is no hope of ever understanding it fully. While often disorienting and distracting, the digressions are always relevant to the narrative. However, they usually raise more questions than they answer.
It is important to note that some of the encyclopedic knowledge is real, while some is fictitious. For example, Wallace references real political events like the Nixon-Kennedy debates of 1960, but he also makes up fictional future events, like the assassination of Rush Limbaugh. He spares no detail in either case, even inventing infrastructure for a fictitious merger of the United States with Canada and Mexico. The way the novel plays with the truth is partly connected to its engagement with speculative fiction (it predicts a near future) and satire.
The semi-truthfulness of the novel also connects it to hysterical realism. This genre juxtaposes absurdity and hyperbole with careful, well-researched depictions of the real world. The combination is a way for books to embed social theory into fiction. Instead of simply representing the world as it is, hysterical realism comments on the real world by exaggerating aspects of it. Infinite Jest often uses absurdity and hyperbolic language to do just that. For instance, Ennet House initially requires residents to follow an extreme version of the AA program that requires them to eat rocks. By exaggerating AA in this way, Wallace is able to raise questions about recovery programs and their regimented rules. Throughout the novel, absurd comedy like this often delivers deeper, painful truths about society and mental health.