Occupy Wall Street celebrated its six-month anniversary yesterday in Zuccotti Park with a fast-forward replay of last fall: re-occupation, carnival, violent eviction, defiance. A morning chalk-in for families and an early afternoon march around the Financial District (actually, two: one silent and one rowdy) began a day of reunion at the movement’s New York home. As re-renamed Liberty Plaza (or Square or Park) became full once again with hundreds of people, the hardy organizers who’ve spent the winter in meetings and arguments were drowned out by joiners, curious visitors, drummers and reporters. A 24-hour re-occupation was called, and new nonviolent defensive formations were rehearsed en masse. They danced, chanted and held a General Assembly. Numbers swelled to close to a thousand when marches from the nearby Left Forum conference joined later in the evening. The whole day was a welcome reminder that in occupation a magic dwells.