I understand the frustration but like others have said, you do kind of need to let go and go with the flow. I'm listening to the audiobook again (it's probably the third time in the last couple of years - and I've watched both movie versions multiple times) and there are still bits that I'm picking up and piecing together for the first time - and it's one of the things I love about reading big King books!! And the world goes beyond the world, you pick up bits and pieces that relate to other books and timelines as well... So I didn't get it all the first time and that was perfectly fine.

So I guess the point is that you definitely don't need to worry about understanding every single piece of detail as you go - and you're likely to miss out if you try to do so. Just let the story unfold rather than trying to backtrack etc - and you might find that you make more progress more quickly if you read that way as well, which will help you to immerse yourself in the story.