This is Grigori Yakovlevich Perelman, the brilliant mathematician who solved one of the most challenging problems in history. A Russian blogger captured his photo in the St. Petersburg metro, showing him with unkempt hair, a scruffy beard, and worn-out shoes-an appearance that might lead some to mistake him for a beggar.

Perelman was awarded a $1 million prize by the Clay Mathematics Institute for solving Poincaré's conjecture, but he declined the reward, stating: "If the solution is correct, no further recognition is necessary." To this day, Poincaré's conjecture remains the only solved Millennium Prize Problem.

Despite being hailed as one of the most significant mathematicians of our time, Perelman withdrew from the scientific community and severed ties with his colleagues, choosing a life of seclusion. His story is a poignant reminder that monumental scientific achievements often come with solitude.

In St. Petersburg, young people have started wearing T-shirts bearing his image and the phrase: "You can't buy everything." By rejecting societal norms and the expectations of the academic world, Perelman achieved unparalleled success while living a life of simplicity and isolation.