Where does Pip transition from boyhood to manhood?

Pip begins the transition from boyhood to manhood after he goes to London in Stage II; then in Stage III of Great Expectations, Pip reaches full maturity.
Before he goes to Satis House to play with Estella at Miss Havisham's Satis House, Pip is an innocent boy. But after Estella is cruel to him and calls him "common," Pip perceives himself as inferior; consequently, he desires to be a gentleman and attain a social status that cannot be ridiculed. This urgent desire of Pip's to become a gentleman seems possible after Mr. Jaggers arrives with the announcement that Pip is to have "great expectations." Elated that his wish may come true, Pip leaves his sister and Joe without misgivings and takes the stagecoach to London. There he lives with a relative of Miss Havisham's, Herbert Pocket. They become fast friends, but both of the young gentlemen do not exercise frugality, and so they get themselves into debt. Worse than this, Pip becomes a snob. When Joe Gargery, whom Pip has loved like a father, comes to London to visit, Pip is embarrassed by Joe's speech and his awkwardness in his new clothes. When the perceptive Joe realizes that Pip is ashamed of him, he returns to the marshes.
After this visit, Pip continues on the path of believing that social position is equated with happiness. However, as Mr. Jaggers has warned him, he "goes wrong." Pip loses sight of the values that are real. When he learns that Estella is coming to London, Pip is convinced that Miss Havisham means for him to court her. However, he soon realizes that Estella is interested in a brutish young man named Bentley Drummle. To add to his disappointment and dismay, Pip is visited one night by Abel Magwitch, the convict from the prison ship. Pip learns from Magwitch that this old convict, not Miss Havisham, is his benefactor (Ch.39).
In Book Three, it is after he and Herbert try to help Magwitch/Provis elude his enemy Compeyson who has come to London to kill him that Pip begins to realize a person's social position is not the most essential quality that someone possesses. It is then that Pip reaches full maturity as a man. The love that Joe and Magwitch have for him is real, and it is love that matters the most. Unlike social position, which has brought no comfort or delight to Miss Havisham or Estella, love provides a person true happiness.