The 2399 days of Ghibli and Hayao Miyazaki

How did Hayao Miyazaki (82), director of films like "Nausicaa of the Valley of the Wind", "Castle in the Sky", "My Neighbor Totoro", "Porco Rosso", "Princess Mononoke", "Spirited Away", "Howl's Moving Castle", "Ponyo" and "The Wind Rises", create his latest film "The Boy and the Heron"? The story unfolds itself behind the scenes during the production, spanning 2399 days.