El infinito placer de las matemáticas has become an unexpected bestseller, with almost twenty thousand copies sold in Spanish alone. The author, the Spaniard Alessandro Maccarrone, holds a PhD in Theoretical Physics from the University of Barcelona, and is a science educator and secondary school teacher. For the last 15 years he has been working as a teacher and popular educator, and he has discovered that physics and mathematics are not only infinite in breadth, but also in depth, and that in the most basic and everyday questions lies a great wealth, complexity and beauty. In conversation with Azael Paz Aliaga.