Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it. When we enquire into any subject, the first thing we have to do is to know what books have treated of it. This leads us to look at catalogues, and at the backs of books in libraries.(in Boswell's Life of Johnson)It's interesting to see that he makes a distinction between knowledge and meta-knowledge, calling the latter "information." It's also interesting to see that since 1775 the second kind of knowledge (meta-knowledge, that is) has increased almost exponentially as compared with the first kind. Some people lament this. I believe that it is an inevitable byproduct of the growth of knowledge of the first kind, and therefore not to be lamented, but to be better understood than it is even now.
In any case, this distinction is one of the reasons why the claim that nowadays there is "too much to know" is, strictly speaking, nonsense.