No need to restrict knowledge to science. But I think the point was that there is a limit to knowledge, including scientific knowledge, and that is why you don’t know things. Or is there something else going on?
Sorry, I think we may be talking at cross purposes. My original post was to point out that some people seem to think that the answer ‘I don’t know’ to a question is unsatisfactory. I take a polar opposite point of view. If one doesn’t know, it’s the only mature and honest answer to give.
I don’t believe that there is a limit to knowledge per se. Only a limit to our knowledge at this moment in time and it is this lack that drives our curiosity.