I started my writing life as a pantser. All I had was an idea, a setting, a couple characters, and I was off. I did what Stephen King told me to do, and wrote my 2,000 words a day. A few months later, I had a big monster of a first draft ... which needed a monster rewrite. And then another. Five plus years later and it's still not there yet! I've had better success with other manuscripts, especially as I've learned more about the three-act structure and proper pitching. But where Brooks would see all that work on my first, unpublished manuscript as a waste of time (or maybe, more fairly, a very inefficient use of my time), I see an invaluable learning experience.