Wow! A dense, extraordinary approach to an auto-biography. Dylan was never going to write a conventional biography, and readers who want one should keep on walking. This isn't for them.
Instead Dylan has constructed a mythology as autobiography. While I think it's fair to assume that everything in this book is true, I think we should probably accept that it's not necessarily literal. He's obviously missed large chunks out for a start - the book really only covers a couple of periods in his life. And a number of allegations of plagiarism that the internet has levelled at him suggest that this is a story of his life during those periods, rather than an exact word-for-word transcript of those events.
Having accepted these criteria for the autobiography, it's a fascinating book, certainly providing an insight into how he sees his own life, and more interestingly, into his state of mind while making the key album Oh Mercy