YOU MAY NOT remember this, but “The Matrix” earned a respectable, yet modest $27 million during its opening weekend way back in 1999. It went on to gross $171 million domestically, an impressive total. (As a rule of thumb, movies typically end up grossing about three times their opening weekend. In many ways this “multiple” is a better indicator of a movie’s impact than its opening weekend performance. Films with multiples of five or six or more–“Titanic,” “The Sixth Sense,” “There’s Something About Mary”–tend to be cultural phenomena, while films with monster opening weekends and low multiples–“Godzilla,” “Planet of the Apes,” “Pearl Harbor”–are often quickly forgotten.) Still, $171 million isn’t what it used to be–“The Waterboy,” Disney’s “Tarzan,” and “Men in Black II” all did about the same amount of business in recent years.

So why is “The Matrix: Reloaded” such a big event? Because “The Matrix” sold some 30 million copies on DVD and VHS–earning about a half-billion dollars for Warner Bros. and more than doubling the size of the installed fan base from the movie’s theatrical release.