However, during his career, this "individualism," says Robertson, "was hidden from public view" and undervalued because, unlike many other directors, Curtiz's films covered such a wide spectrum of different genres. He was therefore seen by many as more of a versatile master technician who worked under Warner Bros.' direction, rather than as an auteur with a unique and recognizable style. Hal Wallis, being the producer of many of Curtiz's films, including "Robin Hood", was always watchful over budgets. He wrote to Jack Warner during the shooting of that film, "In his enthusiasm to make great shots and composition and utilize the great production values in this picture, he is, of course, more likely to go overboard than anyone else ... I did not try to stop Mike yesterday when he was on the crane and making establishing shots." Curtiz himself rarely expressed his philosophy or filmmaking style in writing since he was always too busy making films, so no autobiography and only a few media interviews exist. His brother noted also that Curtiz was "shy, almost humble," in his private life, as opposed to his "take-charge" attitude at work. His brother adds that "he did not want anybody to write a book about him. He refused to even talk about the idea." When Curtiz was once asked to sum up his philosophy of making movies, he said, "I put all the art into my pictures that I think the audience can stand." Before coming to Hollywood, Curtiz always considered the story before he began working on a film. The human-interest side of a story was key, along with having the plot develop as the film progressed. He explains:  His attitude did not change when he joined a large studio, despite being given large spectacles to direct. As late as the 1940s, he still preferred "homey pictures." He said it was "because I want to deal with human and fundamental problems of real people. That is the basis of all good drama. It is true even in a spectacle, where you must never forget the underlying humanity and identity of your characters no matter how splendid the setting or situations are." However, he also felt that even with the same story, any five different directors would produce five distinctive versions. "No two would be alike," he said, as each director's "work is reflection of himself." Film historian Peter Wollen says that throughout Curtiz's career, his films portrayed characters who had to "deal with injustice, oppression, entrapment, displacement, and exile."