According to a recent interview with The Atlantic, former Secretary of Defense and Marine Corps General James Mattis wrote the first draft of his book, Call Sign Chaos: Learning to Lead, entirely in crayon.

"Some of the greatest authors in history have done their best work when isolated from the rest of society where they can think clearly," said Mattis. "So I locked myself in a cabin for three months to write this book. I brought along some crayons in case I got hungry, and I just ended up using them to write the book, too."