Adler and Van Doren suggest that the first and most important rule of skillful reading, active reading, is asking questions and trying to answer them. If you just dwell on that, what kinds of questions should I be asking and how should I go about asking them? How should I go about answering them when the author isn’t present? And so on and so forth. [Unclear] They also say conversely, and this is meant as a criticism, an undemanding reader asks no questions and gets no answers.
Be sure that when you’re reading (or generally consuming) something, you are interrogating it. You can do so on its own terms (“What is this trying to tell me?” “How does it want me to feel?”) - which is good for areas you do not know and things like fiction - or you can do so on your own terms (“How does this match my previous understanding?” “Is this correct?”) - which is good for areas of expertise.