I think a lot is kind of muscle memory. You can't put it into words for reproduction but still you can study it in words.

I imagine that humanoid robots will quickly gain street smarts like autonomous cars are learning the unwritten rules of human interaction. The latter probably do so very explicitly, with engineers approving changes to how the car should behave that were not clear before actually getting into the street. I wonder what Tesla knows about how people expect you to drive according to your location. They must have hard data where humans only have anecdotes.