Derry learned from the fairy tale that he needed to love and appreciate himself. This is evident from the fact that in the beginning of the story, Derry is depicted as a lonely and unhappy person who constantly compares himself to others and feels inferior. However, as the story progresses, Derry encounters a magical fairy who helps him realize his self-worth.

1. Feeling inferior and comparing oneself to others
At the beginning of the story, Derry is described as someone who feels inferior to others. He constantly compares himself to his friends and believes that he is not as good-looking or as talented as they are. This negative self-perception leads him to feel lonely and unhappy.

2. Meeting the magical fairy
Derry's life takes a turn when he encounters a magical fairy who offers him the opportunity to change his appearance and become more beautiful. Initially, Derry is excited about this possibility and believes that his problems will be solved if he becomes more attractive.

3. Learning to love and appreciate himself
However, the fairy teaches Derry an important lesson about self-love and self-acceptance. She explains to him that true beauty comes from within and that he needs to love and appreciate himself for who he is. Derry realizes that he has been too focused on external appearance and has neglected his own worth and value.

4. Overcoming insecurities and making friends
As Derry starts to love and appreciate himself, he gains confidence and is able to overcome his insecurities. He starts to make friends and build meaningful relationships based on his true self, rather than his physical appearance. This demonstrates that self-love and acceptance are important not only for personal happiness but also for forming genuine connections with others.

In conclusion, Derry learns from the fairy tale that he needs to love and appreciate himself. This realization helps him overcome his insecurities, make friends, and ultimately find happiness. By focusing on inner beauty rather than external appearance, Derry discovers the importance of self-acceptance and the value of his own unique qualities.