One finds this theme in full force in Oliver Twist, as, for much of the book, young Oliver finds himself cast about like a leaf in a gale from the most dire of life circumstances imaginable from birth until an incredible coincidence puts him in touch with his true lineage as a cast-off foundling from a much more prosperous class than his tormenters in the workhouse ever know of at first. Oliver gets a taste of the good life until the criminal gang headed by Fagin kidnaps him and spirits him away from his newfound life. The circumstances of Dickens' juvenile life in child labor no doubt inform the utter helplessness of Oliver to the whims of fortune that mark the tone of his book. Oliver Twist came out as Dickens' second book published while still in his early to mid-twenties. The hard life of child labor had to still taste very fresh to him.
Great Expectations appeared as Charles Dickens' last major work, finding serialized newspaper publication as Dickens closed out his life in his fifties. Dickens had suffered a failed, loveless marriage that ended while the author was in his forties, and he subsequently suffered the failed courtship of an eighteen year old stage actress that Dickens might have seen as his last chance at finding true love. These experiences of women doubtlessly inform his characterizations of Miss Havisham and her young, beautiful protege, Estella. Miss Havisham comes on as an elderly spinster who raises the beautiful Estella from childhood for the sole purpose of breaking the hearts of the male of the species. Miss Havisham wears the same wedding dress she wore as a young woman, who, jilted at the alter by a rogue, vows revenge through the upbringing of Estella as a heartless bitch-goddess. Pip finds himself hopelessly enamored of Estella from boyhood, all while suffering from the delusion that Miss Havisham serves as his mysterious benefactor that bestows a gentlemanly station upon him at the arrival of his eighteenth year. For all of Dickens can-do pluck, he never found the love he longed for, and might have worked himself to death in his late fifties, as he toured Great Britain giving physically demanding readings of his works, perhaps as an effort to ward off the despair brought upon him by this central failure in the face of encroaching old age.
Great Expectations holds the general regard as Dickens' best book, but the visceral brutality in Oliver Twist really lays bare the hardship of life for England's lower classes in his times. I imagine the overwrought sentimentality found in Oliver Twist put the tongues of twentieth century critics of such tendencies into a never-ending scolding clucking that attempted to rattle a previously unassailable literary reputation, but hey, Dickens and his depictions of the hardships of his times initiated an attempt for art to bring that stuff to light that ran through the rest of the nineteenth century in books such as Uncle Tom's Cabin, and influenced the attempts to form more humane welfare states in the developed world in the twentieth century.