So, the medium article headline (I have forgottem more javascript than most people ever learn) is actually a reference to neuromancer:

"The Japanese had forgotten more neurosurgery than the Chinese had ever known"

In the book Case was trying to explain that the japanese had been studying neurosurgery for so long that they had forgotten many things which had become obsolete, an amount of knowledge which turned out to be more than the chinese had ever known.

Having read YDKJS and seen some of Mr. Simpson's talks, I do believe that he is qualified to make such a claim about himself.