‘Like, I Symbolize Sex?’

If you're out of your teens, it's a smidge uncomfortable to watch; Cera may be 20, but he looks all of 15. To the target audience, however, his moves are knee-weakening. The five teenage girls I took to the screening collectively raved: "I stopped breathing for a few seconds, I think," says one, age 14, of the romantic ending.

"He's the perfect beta man," sighs another.

"You read that in Cosmo, didn't you?!" chides a third.

Cera is not the first guy to win admirers with sensitive, "beta" schmaltz. John Cusack, emo man before "emo" was a term of art, is clearly an inspiration. Cera's Nick reads as a nerdier update on Cusack's Lloyd Dobler in 1989's "Say Anything": both are spacey, pondering drifters, with a weakness for raven-haired, alabaster-skinned beauties whose wit and brains—rather than physique—are her most flaunted assets. The difference? The better-looking Cusack played as more socially adept. While Cera simpers, reliant on his bushy, raised brows to convey a range of repressed emotions, Cusack fired off zingy mini-monologues. "I don't want to sell anything bought or processed, buy anything sold or processed, process anything sold, bought or processed, or repair anything sold, bought or processed," Cusack mused in the film, a famous sum-uppance of vague teenage principles.

It's Cera's bashful purity and sense of humor that make him appealing—until a certain age, anyway. "My grade doesn't, like, obsess over people anymore," says my youngest sister, who at 17 has outgrown Cera-mania.

Still, some screen presences remain forever young.

"We have a deal," says a girl at the screening, gesturing to her friend. "If she gets Harrison Ford, I can have Michael Cera."

There's a vast half century between the two, I point out.