There are different types of patterns in literature: syntactical patterns, stylistic patterns, literary movement patterns, etc.
Perhaps one of the best examples of becoming accustomed to patterns and developing comprehension as a result occurs in the reading of William Faulkner's literature. On the initial reading of one of Faulkner's novels, one is confused by the long sentences, the stream of consciousness technique and other stylistic devices. But, after reading another novel by Faulkner, the reader's comprehension increases as she/he becomes accustomed to the style of this author. Another author whose style is a key to the understanding of his themes is Ernest Hemingway. The simple, yet well-structured sentence of Hemingway is indicative often of his characters' intentions to maintain order in a nihilistic universe.
Also, if the reader does some background research on the author, she/he will better understand the themes and perspectives of the literary works. For instance, knowing that a particular author is a Naturalist or a Romantic greatly assists the reader in comprehension of themes, etc. Understanding the elements of Naturalism is, indeed, an advantage to reading the works of such authors as Theodore Dreiser or Stephen Crane which are patterned upon the ideology of this movement.
Put simply, the more one reads, the better reader one becomes. Becoming acquainted with literary devices and styles is unquestionably an asset to better comprehension.
A complicated novel will often include many characters, one central plot, and numerous sub-plots. Pattern recognition allows us to see the relationships between characters, actions, and ideas within the book and also allows us to connect a particular literary work to works or ideas outside the story. Since literature does not exist in a vacuum, seeing these patterns and connections enriches our reading experience.
A good example of internal patterns and external connections may be found in The Secret Life of Bees, by Sue Monk Kidd, a book sometimes assigned to high school students. I don't want to say too much that would give away any surprises in the book, in case you have not read it, but let's discuss some patterns and connections that I have seen in the story.
As the story opens, we learn that Lily, the central character, lost her mother when she was very young. An African-American woman, Rosaleen, takes care of Lily and the household. Lily has a few items that belonged to her mother, and when she is alone, she takes them out and goes over them. One of the items is a photograph of her mother. Rosaleen's mother is no longer living, and she has a little spot where there is a photograph of her mother and some items that are important to her. This is a kind of pattern in the story because both Lily and Rosaleen are engaging in a kind of "mother worship" at their respective "altars." This similarity is also a reflection of a two larger themes in the story, our search for our mothers and our search for spirituality within a religion where there is a "God" more like us than the "God" of male-dominated societies. Another pattern that I can see in the story is that there are two central incidents in which an African-American person and a Caucasian person experience unpleasant encounters with the police, but in which the Caucasian person is let go and the African-American person remains incarcerated. These patterns lend a kind of balance or symmetry to the novel that is part of its effectiveness. There are many other kinds of patterns in the story.
An example of an external connection I have observed is a connection to The Adventures of Huckleberry Finn. In Huckleberry Finn, a young Caucasian boy and an older African-American slave set forth on a journey, both looking for a kind of freedom, in Huck's case, a freedom from "civilization," and in Jim's case, freedom from slavery. In the Secret Life of Bees, Lily and Rosaleen, a young Caucasian woman and an older African-American woman, also set forth on a journey, each of them looking for different forms of freedom. Lily, on a quest for information about her mother, is looking for freedom from her father, who is an unpleasant character, to put it mildly. Rosaleen want to exercise her freedom to vote, a freedom that African-Americans in the rural South found very difficult to exercise in the Sixties, when the book takes place.
If I were unable to recognize patterns, my experience of this book would be impoverished. Keep your eyes open for repetition or "echoes" of actions and idea as you read. You will find that your reading experience is enhanced exponentially!