There is the natural and there is the artificial. There is the world we live in and there is the "world" we create. However, as we create, innovate, and develop, the world we live in subsequently evolves.
For the past decades, we've witnessed the world coevolve with the advancement of technology. These technological innovations have brought many advancements in many different areas of life including communication, education, transportation, health, business, religion, and government to name a few. From the time we wake up to the time we go to sleep, computer technology shapes most of our interactions and experiences. Thus, it is safe to say that technology has greatly impacted people and life (mostly in good ways).
This is the reason I believe that all technology that is created is by default "human-centered"; whether it's apparent to the creator or not. It's hard to escape the fact that every technology that is created affects people directly and/or indirectly and negatively and/or positively. After all, we live in a real world, with real people. This very notion and understanding is at the core of the Human-Computer Interaction (HCI) field.
HCI is grounded at the intersection of human experience and computer technology. On the human side, HCI seeks to understand people and their constructed meanings and experiences formed through interaction with others, the environment and artifacts in therewithin. So on one side, HCI is strongly grounded in people, social sciences, and psychology. On the other side, HCI is grounded in technology, engineering, and design.
HCI is about understanding and translating people's real world interaction and experience into their interaction and experience with computer technology. After all, the world of computer technology is different compared to the natural organic way of life. Thus, for technology to be truly Human-centered and meaningful to people and the world, one has to understand people and their environment--needs, wants, values, strengths, weaknesses, intentions, knowledge, place and space, behaviors, judgements, and all the innumerable facets that make people the complex beings that they are. This is where HCI thrives as a field and I believe this is what places HCI at the forefront of the future of technological innovation for the betterment of life.