Here's my logic: This is one of those cases where hype is threatening to overwhelm a lovely movie. You get your expectations up, and then if it isn't exactly as promised, the next "Napoleon Dynamite" or "Citizen Kane" or what-have-you, you're mad at the movie, which isn't fair.

The fact is, "Juno" is always honest about what it is. From the moment we meet its heroine, Juno MacGuff (Ellen Page), she is the stuff cheerful fictions are made of; a precocious 16-year-old who talks with the assurance of a 65-year-old woman without any hang-ups. She communicates at "Gilmore Girl" speed, but every line of dialogue crackles with an intelligence that feels innate, not practiced.

Juno's self-confidence doesn't mean she doesn't know her own limitations; having discovered that her one sexual encounter, an experiment with her buddy Paulie Bleeker (Michael Cera), has left her knocked up, she quickly decides against becoming a teen mother. Or as she puts it, "I'm in high school dude. I'm ill-equipped."

Abortion is on the table, but Juno decides to seek adoptive parents instead. The leading contenders are Vanessa (Jennifer Garner in a truly touching performance) and Mark (Jason Bateman), a picture-perfect pair of yuppies who can't have children.

"Juno" represents a change of pace for director Jason Reitman, in that his last movie, "Thank You For Smoking," featured people who were entirely not nice, while in this one there's hardly any evidence of people behaving badly. Juno's father (J.K. Simmons) and stepmother (Allison Janney) greet her announcement with dismay, but never anger. Their love for Juno is too fierce and unwavering.

As it should be. The girl is lovable, even while trying to deliver witticisms through teeth that are clenching a pipe. A teenager carrying around a tobacco pipe? Pretentious? Yes, absolutely. But actress Page can get away with it. This tiny 20-year-old, who carried a somewhat dubious revenge fantasy called "Hard Candy" on her slender shoulders at 17, is a dynamic, exciting talent.

There will be people who proclaim "Juno" precious and studied. And certainly there is something potentially exhausting about the way Cody rolls that humor at us like a snowball headed downhill. The movie is at its best when it stops and takes a breath, as it does in exchanges like this: "I didn't think you were the kind of girl who didn't know when to say when," Juno's father says, his disappointment evident. "I don't really know what kind of a girl I am," Juno replies.

What made me find the film so memorable in a year full of terrific movies centered on unexpected or unwanted pregnancies ("Waitress," "Stephanie Daley," "Knocked Up") is its willingness to examine the situation's impossibilities. The movie dares to make us hope for conflicting outcomes, that a child lucky enough to have parents like Juno and Paulie would get to be raised by them, but also that a woman like Vanessa would get the child she deserves.