How do I fully, completely and deeply understand on what I read about a chapter, passage, article, poem, sentence, paragraph, text, etc.?

Answer 1

Reading a passage multiple times often helps. If there are vocabulary words you don't understand in the passage, look them up. You can also make some short notes after each paragraph to note to yourself what the main argument of that passage was. This also keeps you honest; you'll know right away if you didn't get something.

Also, some fiction and poetry is laden with metaphor with multiple interpretations and some stories are meant to be almost indecipherable, in order to give more responsibility to the reader to make their own interpretation of the presented evidence. It isn't always about reading and understanding every aspect of the text.