Why is it important to study and understand the origins of humans?
Studying the origins of humans helps us to understand who we are, what we do, and where we fit in as humans. Looking at how Homo sapiens came to be, as well as considering our hominid and primate ancestors, tells an important part of the story of evolution.
Studying anthropology and the origins of humans can enrich understanding in almost any field of study. Even a mathematician should be interested in how humans developed a system of numbers and mathematics. What kind of changes in the brain enabled us to learn math? What might these changes in the brain have been in response to?
Even people with no interest in evolution or the hard sciences can benefit from studying human origins. As a species, we have a strong desire to make sense of where we fit in in the world. Why do you think religion (including folk or informal worldviews) have developed in every human culture? We want to make sense of the world and our place in it.
I hope you will check out the Smithsonian Institute's webpages on Human Origins, if not to help answer your question, at least because they have one of the most comprehensive websites on human origins that is accessible to the public.