The thing about Mr. Micawber is that he is incredibly eloquent and well-spoken, but he is also criminally bad with money.
We've all known guys like Mr. Micawber: really funny and nice, but constantly mooching, borrowing money, and avoiding collection agents. But Mr. Micawber takes it to the next level of extreme: he actually gets arrested for all of his debt troubles while David is still living with him in London.