Reid opens I’m Thinking of Ending Things with the argument that only thoughts are truthful while actions or behaviors performed in front of others can be dishonest and unreliable. Because a thought can’t be “faked,” thoughts are the only reality. Jake returns to this theme frequently in his writing and questions the actions of others as manifestations of his social anxiety and isolation. Furthermore, the narrative structure of the novel supports this theme of the truthfulness of thoughts, as the protagonist’s thoughts account for the majority of the narration. Reid thus invites his readers to pay closer attention to the thoughts conveyed by the protagonist and through her conversations with young Jake rather than concentrating on the plot-based actions each perform.

The protagonist’s thoughts and how they are focused on making the decision to “end things” present a unique narrative structure that reflects this theme. “We’re never inside someone else’s head. We can never really know someone else’s thoughts. And it’s thoughts that count. Thought is reality. Actions can be faked” (162). That actions can be faked corresponds to dishonest people, such as Jake’s mother’s friend Ms. Veal who he believes, despite her seeming cheerfulness, poisoned his mother.