Why did Portugal become a pioneer in the field of navigation?

Portugal is a small country by the sea. She could not compete with Castile (and later with a unified Spain) in the east. Her chance is the development of overseas lands.

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.