Unemployment, juvenile behaviour and a rudderless existence are so much sexier in cinema than in real life. Someone who can't accept they have reached adulthood and insists on going nowhere slowly lying on a sofa is amusing, quirky and even endearing on film - particularly if the person looks like Keira Knightley.

Megan (Knightley), 28, keeps telling everyone she is about to sort out her work/play situation but is perfectly happy to help out her dad (Curb Your Enthusiasm's Jeff Garlin) as a pavement sign-spinner for his tax firm and make silly jokes.

Her sensible girlfriends are all getting married and having children, but the sighting of her father being fondled by another woman together with a proposal from her live-in boyfriend (Mark Webber) and the chance to be godmother to a baby christened Juppiter (yes, two p's) drives her into the company of teen Annika (gorgeous Chloe Grace Moretz from Kick Ass). What Annika really needs is a mum, as her own felt ill-equipped for the job, and though her divorced dad (Sam Rockwell) questions the unlikely friendship, he soon sees the charm of skateboard-loving Megan. Rockwell lives up to his name in Lynn Shelton's film, delivering the sort of performance that is irresistible to women and his knack for staggering dialogue with deliberate pauses makes his character interesting and believable.

As one of cinema's resident beauties, Keira Knightley fulfils her visual responsibilities and the demands of an American accent, but is also quite lovely as the much maligned Megan who is not nearly as wayward and directionless as the story wants us to believe.

Most of the time she is actually quite sensible, though not even the teens are strident rule-breakers in this movie. Attending an evening-in thrown by 15 year-olds and making lewd remarks on a hen night is not enough to suggest Megan is stuck in a rut and neither is a career quandary. So what we have is a nice little love story that is pleasant, but sort of pointless.