THE thing that interests Judd Apatow, Hollywood's pre-eminent director (four titles) and producer (40-plus) of a certain type of relationship comedy, is, he says, ''the basic human struggle to not screw it up''.
And in the latest outing to bear his name with pride, The Five-Year Engagement, the struggle is as long and fraught as the title suggests.
Five-Year Engagement - trailer
The trailer for Five-Year Engagement.
With the likes of The 40-Year-Old Virgin, Knocked Up and Forgetting Sarah Marshall, Apatow has crafted a one-man comedy sub-genre that combines juvenile gross-out elements with serious adult themes - particularly that of masculinity in crisis.
''I think that all men are trying to figure out the balance between being a hunter-gatherer and a nice normal person in a relationship,'' Apatow says. ''We all have to pretend we know what we're doing but we really don't, and we're all pretty much a mess inside. Some people are just better at hiding it than others.''
It's not exclusively a male thing, he says, and his smash from last year, Bridesmaids, is testament to that. ''When you're trying to get through the day and you have all the wounds you carry around from how you were raised, there's a good chance you're going to lose your mind on somebody,'' he says. ''And that's fun to watch, especially when it's not you.''
In The Five-Year Engagement, the unravelling is mostly done by Tom (Jason Segel, who co-wrote the film with director Nicholas Stoller). A top chef, he feels his life coming undone after he moves from sunny San Francisco to the frozen midwest for the sake of his fiancee Violet (Emily Blunt).
While she climbs the ladder of academia, he takes the snake ride down from head chef at a temple of gastronomy to sandwich hand in a local deli.
''A lot of people say, 'Why would Tom move across country and give up his job so she can pursue her dreams?' but you would never in a million years ask that question if the roles were reversed,'' says Segel.
''I think it's actually quite sexist to even ask that question. It's what we would expect a woman to do for her husband, so why wouldn't we expect a husband to do it for his wife?'' The film reflects the fact that ''gender roles are finally equalising and some men's egos are having a hard time catching up with that phenomenon'', says Segel, who has worked with Apatow repeatedly since being cast in his TV show Freaks and Geeks as an 18-year-old.
The Five-Year Engagement is, he says, ''a more adult Apatow-type movie … it harks back to movies like Annie Hall that are comfortable to have a calm exploration of relationships''.
One thing it's got that no previous Apatow film had is Jacki Weaver. Her role as Violet's uptight and bitter English mother is smallish but notable in at least one respect: it's the first cab off the rank in her late-blooming Hollywood career. In November, Weaver will rack up 50 years as a professional actor. She made her film debut in Stork in 1971 and over the next four decades made 15 feature films, a roll call punctuated by a couple of decade-long spells between pictures. She wasn't ever out of work - there were plenty of TV and stage roles for her - but nor was she always top of mind when it came to casting Australian movies.
''You can't complain,'' the 64-year-old says. ''If people don't want you, they don't want you. Occasionally there would be a film and I'd think, 'I could have played that role and nobody even thought of me'. I never thought, 'I could have played that better' - well, maybe I did a few times. But more often I thought, 'God, I couldn't have done that but it would have been nice to be asked'.''
That all changed, though, when she was nominated for an Oscar for her role in Animal Kingdom in 2011. Suddenly, Jacki Weaver was on the radar in America.
''My whole life has changed, it really has,'' she says. ''Not that there was anything wrong with my life before.''
She's made 11 trips to the US in the past two years, ''none of which I've paid for'', she adds with a girlish giggle. She's made three movies and worked with Shirley MacLaine, Nicole Kidman and Robert De Niro.
There's a pilot for HBO in the can and a role in Charlie Kaufman's new film. The highlight of her Hollywood adventure so far has been playing De Niro's wife in The Silver Linings Playbook, due out later this year. ''That took some beating,'' she says. ''In fact I don't think it will ever be beaten.''
Two years into a phase of her career she never sought or expected, Weaver says she still can't believe it.
''And if it all disappeared into the ether tomorrow, I think I could deal with it,'' she adds. ''Because it has all been so unexpected.''
The Five-Year Engagement is out now.