This photo shows Grigori Yakovlevich Perelman in the Saint Petersburg subway.

He has uncombed hair, a thick beard, and worn shoes.
At first glance, he looks like an ordinary person.

But he solved the Poincaré Conjecture, a math problem that remained unsolved for nearly 100 years. It was one of the seven Millennium Problems, each with a prize of one million dollars.

Perelman solved it and refused the prize money.
He also declined the Fields Medal, one of the highest honors in mathematics. He did not attend ceremonies or give interviews.

After publishing his proof, he left academic work and chose a quiet life in Saint Petersburg. He stayed away from conferences, institutions, and public attention. People who knew him say he did not like competition, disputes over credit, or the politics of academic life. He cared more about correct work than recognition.

Over time, he stayed out of the public eye. Still, many young people see him as an example.

Some people even printed T-shirts with his face and the line:
“You can’t buy everything.”

Perelman’s story shows that important achievements do not always come with public recognition.

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