Ben Stiller stars in 'While We're Young'

DON'T LET me hear you say life's taking you nowhere.

Those are the first words of "While We're Young" but they're hidden behind the instrumental notes of an old Bowie song, so you only hear them in your mind, and probably only if you're a certain age.

That age being somewhere in the vicinity of 40 - the age of Josh and Cornelia (Ben Stiller and Naomi Watts), childless mid-life Manhattanites wavering between their having-babies contemporaries and the younger, hipper couple (Adam Driver, Amanda Seyfried) with whom they've become infatuated.

For awhile, director Noah Baumbach ping-pongs Josh and Cornelia between these two worlds, and it's great fun. Baumbach is a gifted observer - he hears, sees and records the foibles of urban/educated/artistic people. His movies, at their best, are a kind of fun-house mirror that reflects and refracts their behavior in an amusing way.

You might say that Baumbauch has a near-documentary eye for social nuance, so maybe he puts a bit of himself in Josh, a once-celebrated documentarian whose second film is a sophomore jinx that's lasted eight years. He's also chafing in the long shadow of his filmmaker father-in-law (Charles Grodin).

So, Josh is energized when aspiring filmmaker Jamie (Driver) flatters his obscure work, and asks for collaborative help.

Baumbach does some smart things here. He draws generational comedy in broad strokes, but flips the paradigm - the older couple is hip to technology, their younger counterparts listen to vinyl records, watch Joe Dante movies on VHS, type on an IBM Selectric.

This dovetails into Baumbauch's ambitious examination of the idea of authenticity, which gets knotty and plotty. (Be careful about reading reviews, because most give the game away.)

"While We're Young" ultimately gets lost in all of this and in a few big, speechy and/or slapstick-y scenes that seem to belong in a Judd Apatow comedy. ("Neighbors" and "This is 40" share Baumbach's interest in the age-related anxiety.)

Baumbach, though, wrestles with something those more mainstream movies do not - failure, the third rail of American commercial movies.

Josh is flailing and failing, making do with diminished and more realistic expectations.

He wants to recapture the energy of youth, but he's prompted to remember that such energy is careless. It wrecks things. Josh is past the point of romanticizing "creative" destruction. He wonders what he can save.