how we read and take in the story is vitality important, thats my opinion anyway, i knew someone who could really read well and fast, but the story didnt filter through and she couldnt remember what it was about, so effectivly books were just books with lots of words but no meaning.
What we read is important .How we read it is up to the individual .Lots of people can speed read and leave out whole passages of books but still get the gist .
I read an awful lot of crime and thriller novels for my sins and race right through them and enjoy them but could never tell you six months later what they were about .They just gave me a good thrilling read at the time and passed the time of day or kept me entertained on a trip or something.So they are not that important .
The important stuff like classic novels that have stood the test of time etc stay in the mind for some reason and I can remember years later what they were about and they are the sort of books I read over again ..I am reading Rebecca at the moment for about the fifth time !! But I would never read a thriller twice !!