Robin Williams portray the deep-driven man. From Dustin Hoffman, with whom he co-starred in "Hook", he learned to take on totally different character types, and to transform his characters by extreme preparation. Mike Medavoy, producer of "Hook", told its director, Steven Spielberg, that he intentionally teamed up Hoffman and Williams for the film because he knew they wanted to work together, and that Williams welcomed the opportunity of working with Spielberg. Williams benefited from working with Woody Allen, who directed him and Billy Crystal in "Deconstructing Harry" (1997), as Allen had knowledge of the fact that Crystal and Williams had often performed
Robin Williams valued the way he worked highly personal issues into his comedy routines, especially his honesty about drug and alcohol addiction, along with depression. According to media scholar Derek A. Burrill, because of the openness with which Williams spoke about his own life, "probably the most important contribution he made to pop culture, across so many different media, was as Robin Williams the person." Williams created a signature free-form persona in comedy, in a style that was so widely and uniquely identified with him, that new comedians imitated Williams personally. Jim Carrey impersonated his Mork character early in his own career.