Final answer:
Juan's belief that Chelsea broke up with him because he didn't call her back the other night is an example of adolescent egocentrism, a concept in Piaget's theory of cognitive development that describes teenagers' tendency to focus on themselves and believe that their experiences are unique and not understood by others.
Step-by-step explanation:
Juan thinks the reason Chelsea dumped him is because he didn't call her back the other night. According to Piaget, this is an example of adolescent egocentrism. In Piaget's theory of cognitive development, egocentrism during adolescence is characterized by the belief that others are as preoccupied with the adolescent's thoughts and appearances as they are themselves. This often manifests in teenagers interpreting events around them as being directly related to them. Piaget observed that egocentrism in adolescents leads to the belief that their own experiences and thoughts are unique and not understood by others, which is sometimes referred to as the personal fable. A similar behavior is observable in young children during the preoperational stage, where they exhibit egocentrism by not being able to take the perspective of others, assuming that other people see, think, and feel the same way they do.