I feel like expecting to remember all arguments and examples in a book is missing the point. You can only summarize it that way because you have already interna

I feel like expecting to remember all arguments and examples in a book is missing the point. You can only summarize it that way because you have already internalized all background knowledge, right? When you can reduce the core take-away from a book to a paragraph or something you assume a lot of context and pre-existing knowledge. An author can't exactly know what the knowledge-level and amount of surrounding facts the reader has available so these have to be provided to support the main point. You could of course provide only one example per point, but then it's sometimes hard to know if the reader takes away the 'right' conclusion from your example so if you provide multiply it's easier to get the through line of the provided examples. When you have built up enough ground to place your main point into the readers brain, the supporting facts become less important to remember (barring one or two evocative examples) so they fade away, but you still have the meta knowledge of your brain having read and vetted the supporting arguments/examples, which you wouldn't have if the whole book was just the main point without all the surrounding detail.