Eric Carmen was on to something. Of all the scary visions and horrible emotions A Christmas Carol describes, there is pretty much none that is quite so overwhelmingly devastating as being all alone. Over and over again we get to check out people who have been geographically or mentally isolated by their life circumstances. In all of these cases, everyone we see struggles as best they can to reverse the isolation and to seek out other humans to hang out with because, you know, that's what humans do. That's what makes Scrooge such a monstrous weirdo; he has isolated himself rather than being forced into that state.
Questions About Isolation
Why does the novella give Scrooge a family member (Fred)? How would the story be different if he had no living family at all?
Can we connect the fact that Scrooge chooses books rather than people for company during the lonely Christmas holidays at school as a boy to the fact that he lives in self-imposed exile as an old man? How does this change our perception of him? Or does it not?
In the novella, it's important that Scrooge is isolated not only from companionship with other people, but also from economic transactions with them. Why? How are the two similar? How are they different?
Chew on This
The scenes of people buying the preparations for Christmas celebrations are, if anything, even more important than the scenes of people actually having Christmas parties.
The person Scrooge is most isolated from is actually himself, and the novella is a long journey of the man coming to recognize his own humanity.