"This Is 40" is a bull's-eye zeitgeist comedy, a movie in which everyone acts like real people but funnier. In his fourth directorial outing, Judd Apatow gives us plenty to feel good about. There's a humane empathy for his flawed characters as they grapple with marriage, family and encroaching middle age. There are plenty of pointed one-liners that will strike a common chord with audiences, and a percolating cast of comedians -- Paul Rudd and Leslie Mann, Apatow's wife, as the harried couple, Iris and Maude Apatow as their young daughters, Albert Brooks and John Lithgow as their fathers.

Everyone on screen is charming and maddening in equal proportion. This sort-of sequel to "Knocked Up" is wise and satisfying, and often sharp and hilarious. After the slight stumble of "Funny People," Apatow is back in form.

The setting is familiar Apatow territory, the luxe but stressed world of Los Angeles creative types. Pete and Debbie (Rudd and Mann) run a struggling indie record label and a profitless fashion store, respectively. They share parenting duties with 13-year-old Sadie (Maude Apatow), a bright, emotional hurricane, and 8-year-old Charlotte (Iris Apatow), a cherub with the comic timing of a standup pro. 

The couple, who turn 40 just days apart, are doing all they can to deny the calendar. She works out with a trainer to keep sag at bay. He eats cupcakes and bikes all over like a kid. He has an enduring love for the music of his youth, struggling to market '80s rocker Graham Parker (nicely playing himself as a wise old coot) to today's audience.

He retreats to the john to play Scrabble on his iPad, and to music bars to listen to a procession of real-life musicians. She goes out to clubs to dance and flirt.

Neither is very good at managing the practical side of daily existence. They alternately over-monitor the kids and ignore them. They set themselves up for trouble by having children before they were done being children themselves, though they blame their problems on their own imperfect fathers. Lithgow is a distant WASP iceberg and Brooks is a needy, guilt-inflicting failure. "It's them, not us," Debbie says. "Totally," Pete agrees.

The film is a comic-therapeutic journey to self-awareness that requires much banging of heads against brick walls. There are funny-profane scuffles with parents and kids at their daughters' school (they provoke Melissa McCarthy into firing off a magnificent, foul-mouthed rant that approaches free verse). Only when a couple of medical surprises strike do they take accountability for their own shortcomings.

When Rudd's Zen punch-in-the-head moment arrives, it's delivered by a gruff guy old enough to be his father, but in much better control of his life than Brooks' character. The moral here is, "grow up already," the only way your life will improve is by setting adult priorities and working hard at them. That's the message of every Apatow film. He has pushed his way to the forefront of American comedy by delivering common sense in funny, insightful packages.