Multi-nipple is due to the development of all glands of the milky lines, which are laid in embryogenesis. Apparently, there is a violation of the reduction processes in the embryonic epithelium of the glands. As a result, the glands develop. The preservation of these structures in the postembryonic period is an atavistic sign that proves the unity of the origin of humans and animals.
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.