What is the big kick we get out of watching people make stupid mistakes in the movies?

Horror movies trade on it -- audiences talking to the screen "Don't go in there!" -- as does "Chasing Amy," although on a much more cerebral level.

"Chasing Amy" is a romantic horror movie, full of moments like the one in which Holden (Ben Affleck), in unrequited romantic frustration, declares his love to his adorable lesbian friend Alyssa (Joey Adams). You sit, gripping the arms of your theater seat and thinking "Don't be an idiot! She's gonna bail on you, don't do it! You're going to look like a fool!"

And then he does it. And she bails.

This is a movie about positively magnetic dopes. Cult comic book creators Holden and Banky (Jason Lee), best friends since childhood, meet up-and-coming artist Alyssa at a comic book convention and Holden is, quite naturally, smitten since Alyssa is a walking male fantasy -- flirty and funny with a childish sensuality and a killer smile (but a voice like Jennifer Tilly) -- who can hold her own against these smarmy and wise-cracking guys.

When she invites them to a club that night, Holden thinks he's in like Flint. He and Banky aren't tipped off by the name of the club -- The Meow Mix -- or by the all-female crowd. They just think they've walked into heaven, not even noticing that half the crowd is very butch gals.

The audience sees what's coming long before these two ignoramuses do, but as written and directed by Kevin Smith that's part of the fun. When the light bulbs finally go off in these guys' heads it's all the funnier because we figured it out long ago.

Holden and Banky clue in after Alyssa tongue-wrestles with her girlfriend before sitting down at their table for a rhythmed dialogue scene that pays homage to "Jaws" and rivals a 1930s screwball comedy -- although the subject matter certainly does not. Alyssa clicks with the vulgar Banky as they swap stories of oral sex disasters while Holden, symbolically, is entirely out of the frame.

Yes, Holden beats into his libido, Alyssa is gay. But it's too late. He's in love.

Alyssa, while at least as clever, thoughtful and witty as Holden and Banky, doesn't seem any more perceptive. She forms a constant-companion friendship with Holden -- all the while being the tease that is in her nature -- but she never realizes that he has the hots for her.

Everyone has been this stupid at least once, and Smith taps into that insecurity. "Chasing Amy" has that nervous it's-only-funny-because-it-isn't-happening-to-me feel.

When the friendship hits the fan, Alyssa walks -- then after a few tense moments, gives in to some hint of dormant heterosexuality and plants one on him.

They become a couple, but Holden discovers she has had a far more varied sex life than she let on. He was OK with past girlfriend because he felt like Columbus planting a flag, but past boyfriends are a different matter. He thought she was just a lesbian because she hadn't met the right guy, when in fact she's had more than her fair share of men already.

Banky also has a problem with Alyssa -- he feels his friendship with Holden threatened by her, which leads him to be as abrasive as possible. "So since you like chicks," he asks her, "do you just look at yourself naked in the mirror all the time?"

Smith's scrutinizing script explores all kinds of singles angst and is relentlessly droll. Even the most serious moments have a thread of comedy running though them. This film, the third in his New Jersey trilogy that includes the celebrated "Clerks" and the panned "Mallrats," is his graduation into grown-up movie-making.

This time Smith's characters have more going on in their heads than they express on screen, affording them a life that goes beyond what we see.

Smith also provides a menagerie of peripheral personalities for some incidental laughs. In addition to a gay black artist who writes a "kill whitey"-themed comic book under a militant pen name, Jay and Silent Bob from the other Jersey movies appear and offer Holden some ostensibly profound romantic advice.

"You're chasing Amy," Bob (played by Smith) says, suddenly not so silent. He recounts a past relationship that parallels Holden and Alyssa's, then falls immediately silent again. The upshot? Bob blew it, and you can call that foreshadowing.