Mathematical logic proves it is impossible to ever know if every single fact has been learned.

A rational mind can accumulate vast amounts of data and even reflect on its own knowledge base. Mathematical logic shows that even a perfect thinker cannot determine if their knowledge is complete or if massive gaps remain. No amount of introspection or new information can provide a final proof of total understanding. This creates a permanent horizon where the unknown unknowns are mathematically guaranteed to exist. You can never reach a state of certainty about the limits of your own expertise.