In Chapter 9, after his first visit to Miss Havisham's house and all the wonders he has seen there, Pip is asked to narrate his experiences to Mr. Pumblechook and Mrs. Joe. Pip feels instinctively that they would not understand what had really happened and what he had seen, so he makes up a story about the supposed riches that Miss Havisham has and her luxurious lifestyle. His audience, including Joe, obviously believes these lies, and Pip feels very guilty, saying "Towards Joe, and Joe only, I considered myself a young monster..." Pip resolves to tell Joe the truth.
When he does so, he tells Joe that he feels "common" now after he has visited Miss Havisham's house:
And then I told Joe that I felt very miserable, and that I hadn't been able to explain myself to Mrs Joe and Pumblechook who were so rude to me, and that there had been a beautiful young lady at Miss Havisham's who was dreadfully proud, and that she had said I was common, and that I knew I was common, and that I wished I was not common, and that the lies had come of it somehow, though I didn't know how.
Although Joe doesn't really understand Pip's outpouring of anguish, he does offer him some sage advice, saying that "lies is lies" and that telling lies does not make a person uncommon, and advises him never to tell lies again. This relates to one of the key themes of the novel, that of good and evil. However, Pip's response has made it clear that his trip to Miss Havisham's house and meeting Estella has made him aware that he is just a "common labouring boy" - he has become dissatisfied with his position in life.