Sadly, that's the problem for me with George Martin - if I had to go back to familiarise meself, I'd be under the ground before I worked out which episode I'd forgotten, got a grip on, or given up on.
And that's without the silly Book 5 - I couldn't remember an awful lot of the character, story lines and sub-plots, because they were completely new, and you need to pretend you know what he's going on about before you can proceed.......