J.D. Salinger's novel, The Catcher in the Rye, has a great appeal to some readers because of its narrative structure. The novel is narrated by the protagonist, Holden Caulfield. Salinger is masterful in capturing the disappointment, disillusionment, and even the angst of the young Caulfield.
However, in one's interpretation of the novel, it is important to remember that everything the reader learns comes from Holden's viewpoint and is biased by his worries, paranoia, and unhappiness. He is truly searching to find a place in the world where he fits, but we cannot be certain that his perceptions are accurate: they are too "colored" by his own personal interpretations. Basically, he is an unreliable narrator. For instance, when he wakes to find Mr. Antolini brushing the hair off his forehead, Holden makes hurried excuses and leaves, though his former teacher and his wife have allowed Holden to crash at their apartment. Holden fears his teacher—his mentor and idol—has made a pass at him, but there is nothing to substantiate this.
The thing that probably most drives us to remember to take what Holden says with "a grain of salt" is that he ends up in a mental hospital—he refers to the "psychoanalyst guy they have here"—at the end, having had a nervous breakdown.