When I started seeing the previews for “Avatar” a few months ago, I predicted that the movie was going to be a failure. It has a weird title, no big-name stars, and a bunch of silly-looking blue aliens.

Well, I was way off. “Avatar” is a mega-hit. It has grossed $400 million domestically and well over $1 billion world wide. The picture is such a phenomenon that I went against my better judgment and saw it.

Again: big mistake on my part. What a terrible waste of an afternoon. “Avatar” is a dumb, simple morality tale that director James Cameron takes nearly three hours to tell.

I am not a fan of James Cameron, but he has truly outdone himself here in terms of arrogance, pretentiousness, and lazy editing.

His previous and finest film, “Titanic,” earned its three hour running time with a good plot, tons of suspense, and characters that we actually cared about. “Avatar” is missing all of those virtues, so its bloated running time is completely unjustified.

“Avatar” tells the story of Jake Sully, a former marine who travels to the planet Pandora in the year 2154 to learn about the alien inhabitants. His job is made easier because he can essentially become one of them. The humans create an “avatar:” a fully functional alien body that Jake controls while his human body is in a sleep-like state.

Jake successfully earns the natives’ trust, and slowly realizes that he feels more at home with them than with his own species.

The reason why earthlings are on Pandora to begin with is because the planet contains a very valuable mineral. The only things standing in the way of the operation are the nature-loving natives who don’t want to see their sacred land strip-mined.

Cameron’s message is insultingly simple: civilized people are bad. Backward people who are in touch with the planet are good. Greed is bad. Environmentalism is good.

The fact that I don’t look at the world that way isn’t the reason why I hate “Avatar.” It’s the fact that Cameron’s simplistic, uninteresting arguments don’t provide nearly enough substance to sustain an entire movie, particularly not a movie this long.

The final battle between the humans and the natives is terribly boring. We know darn well who is going to win, so there is no good reason to drag it out for 45 tedious minutes.

The human villains are so ludicrously evil that they can’t be taken seriously. And the Pandoran natives are so sickeningly pure and virtuous that you can’t relate to them at all.

People with a love of innovative action sequences and special effects may enjoy “Avatar.” Hard-core environmentalists and those with an affinity for Native Americans will appreciate the film’s message. But only people with very long attention spans should see this movie, because it is way way too long.