Reader's Digest, Sept. 1990
During his first year of graduate study at the University of California at Berkeley, George B. Dantzig (later known as the father of linear programming) arrived late for a statistics class. He saw two problems on the blackboard. Assuming they were homework, he copied them and a few days later turned in his solutions. One Sunday morning six weeks afterward, the professor appeared at Dantzig's door, waving a manuscript. It turned out that the professor had merely written two examples of unsolvable problems on the blackboard. The manuscript was Dantzig's work readied for publication.