What is the meaning of Joe's metaphor at the end of Chapter XXVII of Great Expectations?
Here's an excerpt from the metaphor: “Life is made of ever so many partings welded together...Divisions amongst such must come, and must be met as such.”
Shortly after Pip has gone to London in order to fulfill his aspirations of becoming a gentleman, he receives a letter which Biddy has written on Joe's behalf; it states that Joe will come to London to visit Pip. With Pip's transformation in thinking, he reads this letter with a great deal of discomfiture as he worries that Joe will be an embarrassment to him before the young gentleman, Herbert Pocket, his roommate.
With sentimentally humorous descriptions, Dickens portrays the bumbling Joe, whose exerted attempts to be polite and adhere to the decorum of the young gentlemen, become ridiculous as he clears his throat as though he has "whooping cough," he juggles his hat constantly as though
...it demanded from him a constant attention, and a quickness of eye and hand, very like that exacted by wicket-keeping.
and his speech spirals around the topic. For instance, when Herbert Pocket asks if he has seen anything of London, the uncultured Joe mentions a blackinghouse [where Dickens himself had to work as a child] as a point of interest, declaring that it is not as pleasant-looking as the sketches he has seen of it, "as it is there drawd too architectooralooral."
But, although Joe is rather ridiculous in this scene, he is not insensitive to the "mortification" that Pip feels. So, after reporting his reason for coming to London as that of passing Miss Havisham's message that Estella wishes to see Pip, Joe tells Pip that he is going to leave. Surprised that Joe will not stay for dinner; Pip learns that there is a "simple dignity" in the discerning Joe as he states that he and Pip now are divided from one another in certain ways, and they should only be together at the forge in the old way. For, now there is a "diwision" of socio-economic class between them, and Joe feels that he is out of place in London; it is unrealistic for him to think otherwise says that Pip will not find fault in him if he visits and perceives the "old Joe" in his apron and sleeves rolled up. Joe's observation that life is made of "so many partings" means that life has different stages, and Pip is in a new stage where Joe does not belong. However, Pip can yet visit him by returning to an old stage of his life.