Having watched the video and read the text I would like to make only a few additions or clarifications. Graphic design is a tool or a central hub for which information is passed and is the basis for decisions made, trends changed, and problems solved. It is a language that is both universal and unique and it spans across almost everything we see today. It is reliant on both the style and purpose of the designer and the environmental and social constraints. It is a method of visual and physical problem solving that is both as flexible and fluid as the designer. The designer should be themselves, be adaptive, and be purposeful. Design is a practice that must be founded on experience, principles, and successful process, and then brought to fruition through evolution and exploration.
Having watched the video on Stefan Sagmeister I believe he is everything that a designer should be. There is no cookie cutter form for what a designer should be but what he is is himself. Who he is is a culmination of years of professional practice and experimental growth. Essentially there is nothing but himself to hold him back.