Poincaré conjecture proof (2002–2006)
Grigori Perelman posted three papers online in 2002–2003 proving the Poincaré conjecture, one of the seven Millennium Problems. The math community took years to verify the argument, and Perelman declined both the Fields Medal and the $1 million prize.
The proof was validated around 2006; no one claimed the prize because Perelman refused it.
Set the precedent that a Millennium Problem can be solved and the prize declined, and that verification can lag years behind announcement.
OpenAI likewise says it will not claim the prize. The Poincaré case shows how slowly independent verification moves, which is why the Navier–Stokes claim faces years of scrutiny.
