Mosquitoland, 16-year-old Mary Iris Malone, gives readers a limited amount of information. She is an unreliable narrator. Yet she is smart and charming, and we want to believe her as she sets out to save her mother.
We learn that Mim's father married on the rebound, that Mim has not spoken with her mother in months, where she once spoke with her daily, that Mim has been prescribed a drug used to treat psychosis, and that there's a history of it in her family. Readers must piece together the truth between Mim's narrative of her journey, and flashbacks to the past.
Another recent and unforgettable unreliable narrator is Cadence in We Were Liars by E. Lockhart, and a classic is Nick Carraway in The Great Gatsby. Usually it's because there are things the narrator doesn't want to see, other times it's because the narrator needs to construct his or her reality in order to survive.
We as readers must rely upon the author's skill to toggle between the objective truth and the narrator's truth to make the constructed world of the novel hang together. We need to believe that both could be plausible, so that when they come together at the book's end (the narrator's version and the objective truth), we are satisfied. Mosquitoland does that. Quite a feat for a first novel.