The obvious risk involved in adhering strictly to autodidacticism is waywardness. We require the friction of other minds to buff away self-generated roughness. Few of us can polish ourselves. We are likelier to grow cranky and conspiracy-minded, mistaking brainstorms for insight while rediscovering what the rest of the world already knows. Had I read only the books assigned in class, I would today be only nominally literate. Had I read only the books that confirmed the thoughts I already possessed, I would remain marginally illiterate.
I solved this problem by just reading every book. Pick a shelf and get started!