The claim "we do not grow out of it in any sense, even metaphorical" is overly strong.

Consider: The process of evolution is just as natural as (on the one hand) the process of birth and (on the other hand) the process of hydrogen fusing into helium. Considering "the earth" as an agent in the process of evolution is no more peculiar than considering the earth as an agent in the statement "The earth moves around the sun."

The claim "we are not born into this world" is literally false, but if we assume (from context) a philosophical notion of "we are born, tabula rasa, into this world and philosophy is us wondering what to make of it", it is rejecting the notion that humans (or viewpoints, or consciousnesses) are somehow special and atomic, made out of a substance fundamentally incompatible to, say, mud.