The knight was armed with a large sword and a long spear, often used a club and a battle ax, a large shield covered the knight, the body was protected by chain mail (after the armor was changed), and the face was a helmet with a visor. The knights fought on horseback. A blow from such an army could break the superior lightly armed foot troops and cavalry.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.