The horse pulls the cart, and the cart acts on the horse with the same modulus of force directed in the opposite direction. Why is the horse carrying the cart, and not vice versa?
The horse carries the cart, and not vice versa, because the horse, in addition to interacting with the cart, also interacts with the ground, pushing off from it.
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.