I am not sure this is exactly correct. If you download a book that might be copyright infringement. But not if I download a word. How much do they need to downl

I am not sure this is exactly correct. If you download a book that might be copyright infringement. But not if I download a word. How much do they need to download at a time before it becomes infringement? And if the material is never used or displayed to a human is it still infringment (if so, Google is awaiting a huge lawsuit)? Alternatively if I, a human, read a book it is copied into my memory. Is that infringment? What if I quote it? How much can I quote at what frequency before I'm infringing? If I write something similar to the book but in my own words, is that infringment? How similar does it need to be? What about derivative works and fair use? Copyright is a horrible mess of individual judgements and opinions. Written material especially. And the same applies to AI. So now we will get a judgement which is a tech-illiterate judges best guess at the intention of a law written to deal with printing presses not AIs and no room for nuances.