There was nothing special about humans. Nobody, least of all humans themselves, had any inkling that their descendants would one day walk on the moon, split the atom, fathom the genetic code and write history books. The most important thing to know about prehistoric humans is that they were insignificant animals with no more impact on their environment than gorillas, fireflies or jellyfish.
-- Yuval Noah Harari (chapter 1 paragraph 1)

Importance: This demonstrates that humans originated from an evolutionary process like all other animals and were initially unremarkable.

That evolution should select for larger brains may seem to us like, well, a no-brainer. We are so enamored of our high intelligence that we assume that when it comes to cerebral power, more must be better. But if that were the case, the feline family would also have produced cats who could do calculus, and frogs would by now have launched their own space program. Why are giant brains...
-- Yuval Noah Hariri (chapter 1 paragraph 1)