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.