If you’re not familiar with literature from that era, you probably would have trouble with it. Sure, A Christmas Carol seems simple because everyone knows the story from movies and TV, but that doesn’t mean the original story is necessarily easy to read. The passage you posted is a wonderful bit of prose, and very poetic, but the construction of the sentences is not something that you would see in most modern novels. If you’re worried about your ability to read and comprehend books, maybe pick up something more modern and see if you have the same trouble.
Some may call it pretentious, but I don’t really understand why. Sure, you can enjoy a book by only looking at the surface details and not thinking about it very hard. You can just let it wash over you and not look for deeper meaning. Some books are written so as to not even have much more to them than those surface level things.
But you can also look deeper, think deeper, contemplate deeper, and feel more deeply about the things that you read, and overall have a deeper experience with a book if you train yourself to see more deeply into it. There are many books that are written with this kind of experience in mind. Why is it pretentious to point this out?