Ahhh, yes...knowing the original storyline can skew one's expectations.
I am reading the books after each season/episode airs, so its all new to me, and serves to fill out the backstories, and I get to see how they changed the plots and sub plots.
Like the 'frog' people of the marshlands, love their storyline, wish they were included in the HBO series, but can see why they needed to trim that sub-story...movie scripts tend to cut and cut until its a lean mean machine.