A few years ago, I started reading the Dark Tower series, but I only got half-way through "Wizard and Glass". Most of the book being Roland telling his backstory, it just felt like a total showstopper to me. From what we knew at this point, it was already clear after the first chapter set in Roland's youth where that story was going to end, and the longer it went on, the less interested I got. Seriously, this is a story that should have been a spin-off book, or limited to maybe a hundred pages within this book. So after about half of it, I just didn't care anymore, closed the book, and that was that.
I planned to read a summarizing of the book and then continuing with "Wolves of Calla", but I've not gotten around to it, yet. And now it's been a few years.
One of the reasons I started getting back into literary Conan is that the stories, even the novels, are relatively short one-offs. If I don't like a story, I don't have to read it to understand other Conan stories. I may be over the whole series-of-tomes-telling-one-big-story thing. I rather read something short which I actually fully enjoy reading. You know, reading not of a feeling of obligation, but just for my own enjoyment.
Which reminds me, I'm about half-way through Marvel's "Conan the Barbarian" Omnibus, with another collection of Robert Jordan's Conan novels waiting. You know, fun.