" I have in lectures often described this interesting situation by saying: we never know what we are talking about. For when we propose a theory, or try to understand a theory, we also propose, or try to understand, its logical implications; that is, all those statements which follow from it. But this, as we have just seen, is a hopeless task : there is an infinity of unforeseeable nontrivial statements belonging to the informative content of any theory, and an exactly corresponding infinity of statements belonging to its logical content. We can therefore never know or understand all the implications of any theory, or its full significance
Chapter 7 "

― Karl Popper , Unended Quest: An Intellectual Autobiography