Born into a poor farming family in Taizhou, Liu, now in his early 60s, showed exceptional intelligence from childhood. He could memorize classic texts after reading them and taught himself calculus at the age of 11. Throughout elementary and junior high school, he was consistently among the best students.

"I was first in the whole school in elementary and junior high," Liu recalled in a 2017 interview with China’s Sina News.

At 16, he was admitted to the Harbin Institute of Technology with an almost perfect entrance exam score of 398.5 out of 400, majoring in thermal processing. "This score was more than 10 points higher than the scores for key universities," Liu said. "Back then, even getting into university was very difficult."

That year, 3.33 million people took the national college entrance exam, but only 280,000 were admitted. For a rural student, in the early 1980s, entering a top university was seen as a life-changing achievement.

Liu quickly became the pride of his hometown, where villagers called him the "genius boy." His father hosted a feast for the entire village, and residents gathered to send him off to university by boat, accompanied by drums and gongs.

"No one expected that such a golden phoenix could fly out of our small village," the village chief said at the time.

Chinese mathematician Liu Hanqing. Photo from Weibo

Mathematics takes over

As the youngest student in his class, Liu quickly stood out at university. With both natural talent and discipline, he consistently delivered strong academic results, and his teachers placed high hopes on him.

Everything changed in his junior year when he read about Chinese mathematician Chen Jingrun solving part of the Goldbach Conjecture, one of mathematics’ best-known unsolved problems first proposed by German mathematician Christian Goldbach in 1742. Already passionate about mathematics, Liu became deeply fascinated by Chen and the world of number theory after reading the article.

From then on, Liu became consumed by the problem, abandoned his major coursework, and decided to devote his life to number theory, determined, as he later recalled, to do even better than Chen, according to Sohu.

He slept only two hours a day and spent nearly all his time in the library. The university allowed him to do part-time work in the mathematics department while professors monitored his research progress. But faculty members found major flaws in his reasoning and said his methods lacked a solid foundation.

Liu refused to change course. "At the time, I did not care about any of that. I just studied on my own and did not attend any professional courses," he said, adding that he was so immersed in mathematics that he thought of little else.

He ultimately failed to graduate and was forced to leave university. The department head told Liu’s father that Liu had been an excellent student in his first two years but had completely neglected his major courses, leaving the school with no choice.

The cost of obsession

In 1985, while many of his classmates moved into top jobs, including positions in the Ministry of Aerospace Industry and major state-owned enterprises, Liu returned to his village. Back home, he neither found work nor helped with farming. Instead, he continued researching mathematics.

At first, his parents supported him and believed in his ambition. But as the years passed and their health declined, that confidence weakened. Over the next three decades, Liu produced only one academic paper. A friend posted it on an overseas social media platform, hoping experts abroad would review it. A Finnish mathematics PhD reportedly said the work contained too many errors to qualify as a proper scientific paper.

By 2007, Liu’s health had worsened and he could no longer stay awake through the night to continue his work. In 2008, a local school invited him to teach elementary students, but he declined because of poor health.

Today, he lives in an old, deteriorating house with few valuable belongings. Only a single light remains in the kitchen. A few years ago, the village helped him apply for a minimum living allowance of 400 yuan a month. In 2017, former classmates raised money to repair his house, buy him a mobile phone, and set up internet access.

His story has recently resurfaced on Chinese social media, drawing mixed reactions. Some describe him as a man consumed by obsession. Others see him as someone who spent decades pursuing knowledge without caring for wealth or status.

When asked by a reporter whether he considered himself successful or had ever thought about changing his life, Liu gave a calm reply: "What is success? Does having money and a career mean success?"

"I think if you are good at mathematics, that can be called success. As for me, I do not want to change. I may not have material wealth, but I have inner freedom."