Why do you think so much time elapsed between the related discoveries of electric charges (VI century BC) and electric current (late 18th century) – more than two thousand years?
Because the transfer of electric charges from one body to another occurs in a very short time and only after the creation of sources of electric current did the possibilities for its study appear.
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.