Grigory Perelman and the Poincare Conjecture
EagleHasLanded writes "Russian mathematician Grigory Perelman doesn't talk to journalists. Actually, he doesn't talk to anyone anymore. So we'll have to settle for insights via his biographer, Masha Gessen, who, strangely enough, has never talked to him either. But she has spoken with just about everyone who has ever had any significant interaction with Perelman, and the result is the book Perfect Rigor, which more than adequately explains why Perelman has gone into self-imposed exile, and why he probably won't collect the million dollars he won by solving the Poincare Conjecture."
According to http://en.wikipedia.org/wiki/Poincar%C3%A9_conjecture it was solved around 2002