There was nothing through most of that gray, chilly Thursday to suggest that it would come to symbolize one of the great transitions of the 20th century, the triumphant end of a failed system. Even when the delirious crowds surged through the Berlin Wall shortly before midnight on Nov. 9, 1989, it was not because of any momentous decision or heroic feat; it was because of a bad translation, a confused border guard and a natural longing for a better life.