Well, there is no need to fret. Consider that there has been an
  unbroken chain of knowledge passed down from the earliest days
  of Western Civilization. Despite our dramatically received tales
  of loss and regain, instead it appears that there was never a
  time that the classics weren't taught and learned in some form.
  Epicurean values carried on in the Cenobitic monastic
  communities and despite some sense of drama from Justinian I,
  consider the rigor of the Ecumenical councils in general, the
  techniques of the Greeks in logic and Rhetoric as well as other
  schools carrried on. The engineering and sciences embodied by
  Hero, the mathematics continued to be taught and knowledge
  shared with the growing Islamic population, allowing for the
  great arabic mathematicians to publish in the 11th century, and
  even among the struggle of political power for Byzantium between
  the Greeks and the Arabs, schools continued functioning,
  knowledge continued to be shared between the cultures, books
  translated. Sadly, the Latin West was considered somewhat of a
  lost cause by this point as relations had soured considerably,
  although some efforts to bring them back were attempted. This
  narrative I'm giving, I'm not saying that "this is the correct
  narrative as opposed to what is typically received": as you
  know, the very nature of narrative is quite flexible, depending
  on which facets one wishes to highlight. But it was an eye
  opener to me in my 20s to learn that "history as I received it"
  (the tale of inevitable progress against the darkness of
  religious forces and flames) was not necessarily the correct
  story but rather a bit of European chest-thumping. Quite a
  surprise indeed.