In high school, I had a brilliant geometry teacher who would give us a test every Friday. At the end of these tests, he would place an incredibly hard geometry problem, and if you solved it, he would give you a bar of chocolate on Monday. While many of my classmates were worried about the test on Friday, I could not wait for it.

Attaching rewards to difficult math problems wasn’t original to my geometry teacher. In the year we accept as the millennium, **US-based Clay Mathematics Institute (CMI) revealed some of the most difficult unsolved mathematics problems** at a Paris conference and attached **a 1 million dollar prize to each.**

`Exactly 100 years before the said conference, again in Paris, renowned mathematician David Hilbert released `**a list of 23 prechosen math problems**, inviting all mathematicians to a great challenge. That challenge was met with great reception, and the answers to those problems shaped mathematics in the 20th century. **You can find the list of Hilbert’s problems here.**

Twenty-two years after the challenge of CMI, only one of the seven problems had been solved. Russian mathematician **Grigori Perelman** solved the **Poincare Conjecture**, but more interestingly, **he refused to accept the one million dollar prize.**