I've heard Kubrick was one of the very few filmmakers that did not have studio imposed contraints of time or money. As I understand he could take as long as he wanted and even scrapped entire films and started over from scratch because he decided he didn't like one actor during the final cuts. Hardly any filmmaker has that "luxury".
‘He erased the entire project’ … the book Stanley Kubrick didn’t want anyone to read to be publishedHalf a century since the perfectionist director vowed to block it, a critique that dared to discuss flaws in his films is to be published