What is the theme in The Catalogue of the Universe by Margaret Mahy?

Becoming one's true self is another theme in this story. Both Tycho and Angela go through various incarnations of themselves throughout the novel, as everyone does when growing up. At the beginning of the book, Tycho is a reserved, bookish intellectual who has not had much experience in the area of romance. His friends consist of Angela (for whom he pines for a different sort of relationship) and the personas throughout history whose words he has tacked above his bed. His family life is one based on rules and expectations: an environment that stifles the development of one's true self.