From a patient look into the history of our relationship with opening sentences comes the following:
Very often, a successful literary first sentence involves some sort of odd yoking. The beginning of Orwell’s Coming Up For Air is typical: “The idea really came to me the day I got my new false teeth.” Not only is there the vagueness of “the idea”; there’s also the question of just what sort of fascinating idea could come from false teeth. Marquez, whose sentences always make the lists, is a master of this technique. His most celebrated novel, 100 Years of Solitude, opens, “Many years later, as he faced the firing squad, Colonel Aureliano Buendía was to remember that distant afternoon when his father took him to discover ice.” Sure, there’s killing going on, but what you want to know about is a simple childhood experience. His second most celebrated novel, Love in the Time of Cholera begins, “It was inevitable: the scent of bitter almonds always reminded him of the fate of unrequited love.” Again, the mystery is human, slight. Like with Orwell’s teeth—how are those things connected?
Read the whole history at Electric Lit: In Search of the Novel’s First Sentence: A Secret History, by Andrew Heisel.