I found it useful when writing a thesis. It gave me a way to research many ideas, not directly connected to the main topic, but still interesting in my mind at least. I really enjoyed this unstructured approach. I didn't have to worry that I will get stuck, because I always had a way back to the main topic.
So, I think you need some kind of a goal, a bigger project, for Zettelkasten to become useful.
Honest question: why would you want to remember what you read? Instead take notes or use post-it notes to mark the interesting bits and you can always come back to them, given you have a good enough system for storing and linking. You can't rely on your memory anyway.
What I have learned is that every behavior serves a inner goal or purpose. You can try to figure out what the goal is by asking "by doing this what am I avoiding or what am I seeking".
Overthinking is when the Law of Diminishing Returns kicks in. You can see it happening every day in the meeting rooms while planning new features/releases, we don't really get any new information but it's comforting to just talk about it.
I don't think I could retype the whole novel, maybe short stories would be more suitable. I remember back in the day when I wanted to be a writer I used to retype short stories just to get out of writers block. After rewriting first few paragraphs I started to change things up and transform into my own story, meanwhile mimicking the rythm and the flow of the original author. It's a good exercise just to get the right feeling.
I own iPhone SE and let's be honest, this phone is designed for people living in warm climate, not someone living in nordic countries. If it's around zero degrees celius or less, then you better not take your phone out of your pocket. The battery will uncharge and phone will shut off(sometimes in matter of minutes). I thought there was something wrong with my iPhone, but it turns out the battery can't stand the cold.
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Otherwise I love iPhone SE. It's almost perfect.
So, I think you need some kind of a goal, a bigger project, for Zettelkasten to become useful.