Many people have this same experience with reading. Barring any unrecognized reading disability, two things are often happening. One, not everyone "sees" in their heads what they read with a movie-like quality, and because of this they often become distracted and do not remember what they have just read. I read just about every book except light novels for fun, as if it is a textbook for school. I annotate in the margins my responses and questions to the material and I highlight what appears to be the most important points. I also will sometimes write a few words or a phrase at the top of the page like a chapter heading to remind me what that page was about. Although this is slow reading at first , it helps people stay focused and present, and it does become second nature after a while. This technique is also really helpful when you want to go back and review a text. For those of you who have a hard time marking up your books, think of them as "tools" that must be "used" to meet your goals. Good reading!
shellycheval