The previous books in the series, he just worked on a little at a time. He used to let the story write itself, which was frustrating because it was five years' wait for each book.

But after that accident, he realized he could easily die before he finished his magnum opus, so he forced himself to wind the story down. In doing so, he didn't give the story time to uncover itself and instead just forced it to go where he thought it should. Four books over 20 years, then three within 2.

I was pretty upset by the whole thing. I had waited fifteen years (I started with The Drawing of the Three), I was in it for the long haul.

Of course, it could also have been that the car accident made him realize he didn't want to write The Dark Tower anymore, and so like a professional, he just finished it as well as he could, rather than just tell us fans to suck it.

Either way, it was a long set-up for not a lot of payoff.