Poincaré conjecture
A 1965 paper of Stallings "How not to prove the Poincaré conjecture" gave a group-theoretic reformulation of the famous Poincaré conjecture. The paper began with a humorous admission: "I have committed the sin of falsely proving Poincaré's Conjecture. But that was in another country; and besides, until now, no one has known about it." Despite its ironic title, Stallings' paper informed much of the subsequent research on exploring the algebraic aspects of the Poincaré conjecture (see, for example,).