When you preview a book you have
your purpose. When some one ask you about it later it's not always possible to explain your purpose because their question came from
their purpose.
Previewing and post viewing is really only used for deciding whether the book will serve your purpose and how, whether you think you'll get anything out of it or in short, Go or No Go (proceed to activation or dump it)
So with those considerations when you are looking at the books you're not focusing on creating a memory of the stucture it's just one of the factors that help you decide whether you want to go further with the book.
It can be explained like this. You see a person with the most interesting eyes and for some reason you want to go up to them and just talk to them. If someone later asked you what type of shoes they were wearing you would not be able to tell them because that wasn't your focus when you decided to talk to them. But you can be certain that the shoes and what they were wearing was an important influence on you decision to talk to them. If the clothes and shoes were attracting flies you might have decided to just walk pass the begger on the street. Even then you might not be aware whether they were wearing shoes or not.
So you are probably doing a whole lot better than you thing.
Alex
