From what I understand he has one of the sharpest engineering minds of our time (he's Chief Product Architect at Tesla and Lead Designer at SpaceX). In his biography, the author said Elon sees the world in blueprints and models. In 2001, during his flight back from Russia where he failed to acquire an ICBM, he said "fuck it, we're designing our own rocket". And came up with the design for the Falcon 1 by himself.