After going to Satis House as a young boy and being ridiculed and called "common" by Estella, Pip feels the sting of being from the lower class and desires from then on to better himself.
Pip feels that good fortune comes to him when Mr. Jagger arrives at the forge and brings Pip the "astonishing news" that he has "Great Expectations." Pip is elated,
My dream was out; my wild fancy was surpassed by sober reality; Miss Havisham was going to make my fortune on a grand scale. (Ch. 18)
Pip then leaves the forge after having been released from his apprenticeship to Joe, and he arrives in London with the promise of becoming a gentleman. There he rooms with the former "pale young gentleman" whom Pip fought as a boy on his initial visit to Miss Havisham's, Herbert Pocket. From Herbert, Pip learns proper table manners, and Herbert's father, Matthew Pocket, acts as Pip's tutor.
In his efforts to become a gentleman, however, Pip seeks to elevate himself by rejecting all that is associated with his lowly childhood. Sadly, he rejects Joe because of his crude manners and discomfort when he comes to London to visit. Further, Pip is critical of his childhood friend Biddy; in short, Pip changes into a snob, rather than a true gentleman, who appreciates quality in anyone who has it. Pip also seeks to ingratiate himself with Miss Havisham and Estella in his desperate love for her, perceiving her as having "indescribable majesty....and charm." He has confessed earlier to Biddy, "I admire her dreadfully and want to be a gentleman on her account." (Ch.17)
Of course, Pip makes the grave mistake of placing material values above spiritual, as he rejects the genuineness and love of Joe, he is repulsed that his benefactor is the grateful, but criminal Magwitch rather than the dysfunctional, but aristocratic Miss Havisham, and he finds Estella rather than the sweet and kind Biddy admirable. Nevertheless, he does change his life, as he learns important lessons in London from Herbert and Wemmick and even Magwitch, lessons that bring him back to the forge to renew his relationship with Joe and revive his love for the kind and worthy man along with the genuine and good Biddy.