reading and retaining

You are probably a compulsive reader, must be if you're reading this. Compulsive readers read cornflakes boxes and are grateful for the French on them (if they're Canadian).  Some people owe their (in)complete knowledge of French or nutrition or astrology or whatever to pick-up reading.  How much do they - you - I - remember of the huge amounts of words, i.e. information, insights, emotions, experiences, psychology, comfort and entertainment that pass "like "light through glass," as one writer put it.  (See? I retained something.)  Is it possible to  choose more carefully What one reads?  Does one want to? We read, I think, as we eat, not content with a constant, unchanging, bland diet, but craving spice, heat and challenge as well as good nutrition. What do we retain?  Indigestion, fat, a restless desire for more, whatever more is.  Oh dear, this was going to be fairly simple but it's getting more complicated as I go along.  Cut to the chase, B.J.  Well, here's one leg of it: have you ever picked up a book, usually a mystery, not recognizing the title, but realizing as you begin to make your way along, that you've read it before.  Of course, you have, and depending on what else is available, you put it down and pick up something else, or you re-read it, marvelling at what you don't remember. So why did you read it in the first place?  What did you retain that was of any use to you? Was it merely a pass-time?  Yes, but.  Now I'm going to take the writer's place: why did he/she write it? It took effort and energy and thought.  Was that all wasted? On you?  Remember Graham Greene made a distinction between his serious books and what he called his entertainments? (Of course, some of his "entertainments" are seriously good; we won't go into that now.)  I think my point is, if there is one, is that everything you have encountered in your reading in some way has changed or defined or added to who/what you are as a person.  "I am a part of all that I have met.."  Oh, and "these fragments I have shored against my ruins."  See, I do retain a few things.