>Yes the book is good for you now, because there was a reason you picked it up in the first place.
I agree in general, but not with that specific statement. Even if there was a good reason you picked it up, it might not be a sufficiently good reason to spend 10 more hours on it, or to block the queue of other books that would be more valuable to you at that point in time.
How do you know the book is (or will be) valuable to you until (a) you finish reading the book, and (b) experience a set of circumstances that make you appreciate the "value" of the book?
Is a period of 10 hours (or however many) spent reading a book _so_ important to one that one must judge a book before picking it up?
I think it depends on the type of book. I agree that you can't really appreciate what value you'll get from literature before reading, digesting and living with it. But lots of non-fiction should actually just be a blog post or some bullet points. There's certainly an opportunity cost to reading those books.
I agree in general, but not with that specific statement. Even if there was a good reason you picked it up, it might not be a sufficiently good reason to spend 10 more hours on it, or to block the queue of other books that would be more valuable to you at that point in time.