> Born in 1955, Zhang could not attend school and taught himself mathematics at the age of 11. He worked in the fields and factories for several years to make his way to Peking University, where he earned his master's degree in 1984.
> Zhang then moved to the U.S. to get a Ph.D. in mathematics from Purdue University. Failing to get himself a job, Zhang then worked as an accountant, a restaurant manager, and even a food delivery person before getting a position to teach pre-algebra and calculus at the University of New Hampshire in 1999, the SCMP report said.
> In 2013, Zhang shocked the world with his twin prime conjecture, which proposed that there were an infinite pair of prime numbers that differed by two. Prior to this, Zhang had achieved only one publication.
29 year old (1984) - Got master degree.
44 year old (1999) - Got first academic job.