To practice design in the 21st century is to use a particular set of tools to engage with the world on all levels, from the social to the technical to the biological and back again. The act of designing is an act that draws upon all aspects of life, all facets of knowledge and experience. To design is to be human. To design is to help people to work, to play, to communicate, to create, and ultimately to live. To be a designer is to perceive, think, and act as a generalist in a world of ever-increasing specialization; to be a master-of-all-trades, an expert dillettante.
People will try to tell you that you can't do everything, that you can't be everywhere at once, that you can't be a Renaissance person.
That's bullshit.
Think and act, then do it again.