Is mathematics beautiful or useful? Why do people choose to do mathematics? How could Enrico Bombieri have been obsessed by the Riemann Hypothesis since the age of 15? How could Andrew Wiles have devoted 30 years of his life including 7 years of isolation just to solve Fermat’s Last Theorem? Indeed, mathematicians themselves nowadays are still arguing about whether mathematics is or should be either beautiful or useful. Are those who do ‘useful’ research occasionally looked down upon by others who do more aesthetically pleasing ‘beautiful’ mathematics research?