That's not necessarily my take from the story---but I can see where you are coming from! The prof was not saying that he does not know anything, he was just elu

That's not necessarily my take from the story---but I can see where you are coming from! The prof was not saying that he does not know anything, he was just elucidating the 'boundaries' of his knowledge. My take was that you can be confident about the skills that you _do_ have, and honest about the skills you _don't_ have.