Kristin Cashore said it at the Simmons College Summer Institute last year, in a speech later adapted for The Horn Book:
Those little things [decisions about characters' quirks and backstories] are essential to every action, every interaction, every line — and you can’t proceed without them. When you start a book, you’re trying to make something out of nothing, and you need it to grow fast. And so, at the beginning of a book, practically every word can cause the writer growing pains.
At the time, I'd just started my current WIP, and though my realistic early chapter book looks and sounds nothing like Graceling, I knew exactly what Kristin was talking about. Getting the first few scenes down meant constantly stopping and asking myself, "Who should talk first? Which of these characters is the type to start the conversation? Would she start with 'hi,' 'hey,' or 'hello,' or just jump right in? Should she pause to take a bite of her sandwich? What kind of sandwich should it be?" (Food plays a major role in my WIP, so that last one was more important than it sounds.) I kept having to wonder, "Should I figure this out now? Or should I just go and fix it later?"
That's what having a new computer feels like. For the past couple of days, every quick task has meant thinking about registering this and installing that. Do I want Firefox to remember this password? Do I want AIM to sign me on whenever Windows opens? (That one's a no.)
There's no official End of the Beginning moment, but there will come a point when I realize the computer doesn't feel new anymore, when opening a document just means opening a document. I know it's coming... at least if real life is anything like writing a novel.