“The more than 7,200 pages now extant probably represent about one-quarter of what Leonardo actually wrote,4 but that is a higher percentage after five hundred years than the percentage of Steve Jobs’s emails and digital documents from the 1990s that he and I were able to retrieve. Isaacson, Walter. Leonardo da Vinci (p. 106). Simon & Schuster. Kindle Edition. Isaacson, Walter. Leonardo da Vinci (p. 106). Simon & Schuster. Kindle Edition. ”
