We got where we are somehow, assuming it really wasn't ancient aliens. Knowledge still got passed down before there even was written language.
If the only people that survived were members of UF, between all of us we'd know how to generate and control electricity, build circuits and engines, formulate concrete, steel, and other alloys, have a decent base of medical and agricultural knowledge, etc. Hell, we'd even have glue, musical instruments, and other forms of art in the first year.
the type of knowledge that was passed down before the written word was not exactly what would recreate modern society. that was stuff like "things are growing where we poop, maybe it's seeds from the fruit that we eat turning into new fruit"