Because there are two narratives in this book, there are two endings. We'll talk about both of them and how they relate to each other.
The first ending is what Shmoop would call an informational one – it ties up some loose ends and gives us some facts we've been waiting for. It takes the form of Brint's final transcript, which is an "Annual report on File Data 865-01" (32.1). The language of the transcript is very technical, which means not only a lot of tough words ("elicit," "corroborate," "recapitulation," "obliterate," to name a few), but even common words, like "terminate," have an ambiguous meaning (does it mean terminate like Arnold Schwarzenegger terminate?). No one is referred to by name, just a label. There's also a condensing of language: parts of speech that help us make sense out of language, like articles and prepositions, are left out. Basically, it's a tough chapter.
The key facts we seem to learn from the chapter are:
First question: What did we miss? Is there any other information we're given that Shmoop didn't catch? And second: What does this all mean?
Here are a few things to consider: Who is Brint? Why is he called T? Is he biased in his analysis, or is he just telling it like it is? What is making Adam forget: amnesia from a head injury? Medication? Post-traumatic stress? What was Mr. Grey's involvement in the car crash? Do you believe Brint's report?
Shmoop doesn't have the answers to any of these questions, and Robert Cormier probably wanted it that way. A good ending often leaves readers with a few lingering questions. I Am the Cheese might leave us with more than a few, but it definitely gets us thinking.
The final chapter of the book serves as the more emotional ending. It's a word-for-word repeat of the opening paragraph of the book. This seems to imply that Adam was not terminated (at least not immediately), because we are back inside his mind. But it also reminds us that he will probably never get better. This chapter is, after all, a repeat of the beginning of the book. It seems that Adam is permanently stuck in a cycle of forgetting and remembering. This ending is actually what brought the most criticism for I Am the Cheese. Most young adult fiction ends with at least a glimmer of hope, if not a full-on happily-ever-after. Here, we get nothing.