How does the firs-person narration affect the plot of mikyla's story

The use of the First person limited narrator,  allows different possibilities for the author,  in the construction of the novel, and the reader in the perception of Pips drama. “Great Expectations” was written during the age of Realism,  so having a character telling his own story is a plausible way of putting the story in order, giving some information and not other, and making you feel that you are reading the story of a real person, not a character.  Also is a way of avoiding the effect of an external intelligence that can see everything, but chooses not to give us all the information.