Almost all of the people Pip knows have specific societal roles with specific societal functions: the tailor, the blacksmith, the clerk, the lawyer, the seedsman, the shipping agent, and all of these people seem content in their lives of earning profit and creating things. Not Pip. His goal is much more vague: a gentleman. What is a gentleman? What does a gentleman do? How will Pip know when he becomes a gentleman? And isn't that vagueness kind of the point? If you can't define it, it's easy for someone else to tell you that you're not one.