The way things go

It wasn't easy writing this book, so unlike any book I ever dreamt of writing. In fact, it's a book I never thought I would ever write. But once I was done with it, and ready to move on to the next one, I didn't think I would ever have to go back to it. Of course, I did have to go back to it.

Not only go back to it but actually rewrite major parts of it.

That's just the way things go.