Juan Carlos Fernandez del Castillo studied math at Harvard, where he lived in Mather House. While at Harvard he did research in mathematical biology, modelling tumor evolution. He also completed a secondary in history, focusing on Europe after 1500. He has a strong side interest in philosophy and theology, and served as Vice President for Intellectual Development of the Harvard Catholic Student Association. Outside of the classroom, he helped put on small concerts for residents of nursing homes, playing piano. While at Harvard he also completed four years of military training through the Naval ROTC program at MIT. At Cambridge, he is completing Part III of the Mathematical Tripos, focusing on geometry and topology.