Stevens is not a reliable narrator for several reasons. The biggest reason is that he often deludes himself, and—as the narrative is entirely in his perspective—misleads us as well. We learn that some of Stevens's assumptions and values are questionable only through other characters' reactions to him in the text. For example, when Stevens decides not to question Lord Darlington's decision to fire the Jewish maids, Miss Kenton is absolutely outraged. As readers, we are willing to grant Stevens the benefit of the doubt, as he is precise in so many other ways, and is very good at his job as butler. But when he indifferently tells Miss Kenton that the maids must be fired, it becomes clear that his willingness to fire them solely for his employer is due to his extreme idea of "duty," not because of the confusion of his historical times. Though Miss Kenton is as good and dedicated a worker as Stevens is, she is so struck by the immorality of the firings that she threatens to resign. Her reaction clearly shows that she and Stevens are not a part of a larger warped, anti-Semitic reality in which it is difficult to tell right from wrong.

Another reason Stevens can be considered an unreliable narrator is because he delays divulging important facts to us until very late in the narrative. Indeed, he gives us only a biased, foggy perspective throughout much of the novel. For example, he fails to tells about the conversation he had with Reginald Cardinal—in which Cardinal says that the Nazis are using Darlington as a pawn for their own aims—until almost the end of the novel. Though Cardinal's words ring true to us, Stevens responds that whatever Lord Darlington is doing must be for the good of humanity, as Darlington is a noble gentleman. Cardinal reacts much as we would: he is incredulous that Stevens can persist in believing that nothing is wrong. At this point in the novel, we understand how completely Stevens has deluded himself, and it is sad: he has completely trusted a man who we now know has made very stupid decisions. This realization gives us further confirmation that Stevens himself is not really reliable. Indeed, we must depend upon other characters in the novel to deliver accurate insights about other characters and events.

In a sense, Stevens's entire journey is a search for the precious jewel he has lost—Miss Kenton. When Stevens's father falls on the steps, he insists he fell because they were crooked, not due to any fault on his own part. After his fall, he is bewildered, and peruses the steps as if searching for a clear indication of how he made such a grave mistake. Stevens's father, like Stevens himself, cannot admit to, or even recognize, his own human fallibility. In Stevens's recollections of his interactions with Miss Kenton, he is constantly searching for where he figuratively "fell" from her good graces. Like his father, his eyes are trained on the landscape of his past; his father's fall demonstrates his own descent into self-deception and eventual regret. Both men's mistakes unrelentingly haunt them.

Both Stevens and Miss Kenton are extremely committed to their work. However, Miss Kenton eventually decides that there are other things in life that are worth striving to attain, like getting married and having a family. The thought of these alternate goals never appears to enter Stevens's head; if it does, he never tells us. There is a moment in the novel when Miss Kenton says that Stevens has comfortably reached the top of his profession, and asks him what more he could want from life. Miss Kenton seems to be trying to unearth any personal goals that Stevens may have. Stevens, however, merely responds that until Lord Darlington achieves all that he can, he himself will never be perfectly contented. This exchange perfectly illustrates how Stevens differs from Miss Kenton: she does not substitute her professional life for her personal, while he does, to the utmost.