He was serious when he made it, even that now he claims he did it on purpose.
But it doesn't really matter, this movie is a phenomenon!
Useless info: Even today, 6 years after its release the movie is still played in some cinemas in US (especially Los Angeles) mostly midnight screenings and it's almost every time sold out. People attended at the cinema dressed as the movie's characters and throw plastic spoons at the screen!
It's also coming in UK the next month for one night and it's already sold out!
Classic!