In 999, it is generally accepted that there is not much left to be learned. All lands have been discovered and just about everything there is to know is now known. All knowledge anyone needs is available in the Bible, and this can be explained by priests to the people. Most men have no need to learn to read, and women and slaves have no such need to learn to read at all, assuming that they are even capable of learning to do so. People need to learn that the sun and stars move around the Earth, and that the king gets his right to rule from god.
Men learn from god, and women learn from men.
Faith and belief is far more important than things learned from books. Most learning is from stories told by the old ones of the villages. In the year 999, they think there are very few places left to discover or conquer. There are some crazy folks who say there are new worlds to find across the sea, but sane intelligent people know this is not true, because if a ship sailed across the ocean they would fall off the edge of the world, and the ships would probable be sunk by sea monsters. Weapons may become more powerful with stronger bows and new inventions like war machines that can throw spears and fireballs many feet farther.