Apart from system engineering Satoshi also masters effective communication.
It is not easy to talk with such clarity and density.
Discussion
Satoshis words: I’m better with code than with words though...
I'd also argue that statement from him
Clear communication does not always require to know thyself.
Satoshi might be the kind of person that underestimates himself, because of his own ultra high standards towards critical thinking, he would never characterize himself as good with word.
But I'm obviously guessing here.