Cave also appears in fleeting staged car scenes with Kylie Minogue, former bandmate Blixa Bargeld and Ray Winstone (star of film The Proposition, which Cave wrote).
"On the one hand it's a fiction, yet more truth can be gleaned this way," notes Cave, 56. "What I liked about the film was it gave me the opportunity to ruminate about things I was actually interested in. This rarely happens in a journalistic interview. I was given the opportunity to write things and talk about things that were unexpected. It was very clear from the start that the film was going to be something very different, about something greater than just the life of Nick Cave, and that's what drew me to it."
He had no intention of telling his life's story.
"We were trying to make a film about things that interested us, the greater ideas about memory and inspiration." In the film, which won the Sundance Film Festival's directing and editing awards in the World Cinema documentary section, Cave speaks of the huge influence of his father, who died when he was 19.
We briefly see his wife, Susie Bick, and for the first time we meet their twin boys, Arthur and Earl (born in 2000), as Cave has one of their "inappropriate film nights" where he shows them Scarface.
"I think cinema was invented in order to show violence," Cave says. "I became invested in cinema because I could do violence in a more satisfying way than writing a song."
"Cinematically it wasn't an appealing idea for us to see Nick driving his kids to school or washing the dishes or whatever mundane normal things that everyone does," Forsyth explains. "It doesn't reveal anything at all, so we wanted to stay within a very heightened reality. I think it's much more inspirational to see the extraordinary, to see the fabulous, to see the people who aren't like us. The great people like David Bowie are on a pedestal.
"He is untouchable - and that's where I want my rock stars, my idols, to be."
Even if Cave comes and flops on the couch like any dad might, he's still wearing his trademark dark suit, which offsets his jet-black hair. This also feeds into the idea of the myth and all the trappings of being a rock star, Pollard says.
Ultimately the directors decided that although Bick has been a huge influence on Cave's life and work - she is the model on the cover of the Push the Sky Away album - they have largely left her out of the film as she would have had too much of a "normalising effect."
Likewise, they left out Cave reminiscing about going boating with his dad and sister.
"Nick is a very open person actually, surprisingly," notes Pollard, "though he is tremendously active and very aggressive and possibly the most impatient person I have ever met. So just keeping him in one place and interested in what you are doing for long enough was the challenge.
"He was remarkably trusting and patient during filming. It was unscripted and he just ran with it, especially in that car scene with Kylie."
The car scenes are supposedly figments of Cave's imagination. Minogue represents an important moment in his life and career when the Bad Seeds were briefly exposed to the pop charts with Where The Wild Roses Grow (which Minogue just revived with Chris Martin in a Sydney concert)
The scenes were shot in 20 minutes with no preparation and as with the rest of the film there were no second takes.
"There was something going on in those car scenes, especially with Blixa and Kylie, in that I hadn't seen these people in a very long time," Cave notes.
"There was some unfinished business with me and Blixa because he left the band with a two-line email and I'd never really spoken to him about that since. We didn't get a chance to hang out for a couple of days before we did this. We just sat in the car and started filming so it set up a very strange tension. It was very moving for me to be in that car with him and to see him again in all his glory and to remember what a pivotal person he was in my life and in the life of the Bad Seeds."
Cave clearly shows his fondness for Minogue -- as well as his wry sense of humour -- when he gets in the car and Can't Get You Out Of My Head is blaring on the radio. He quickly turns it off.
"I hadn't really seen Kylie properly beforehand and we had the most intimate talk that we've probably ever had inside that car with the cameras rolling. Maybe it's got something to do with being a celebrity, of being constantly interviewed, that the most intimate things that get said ultimately are in those weird, false situations.
"That may be one of the tragedies of being a celebrity or whatever you want to call it, whatever creatures we are."
It's not all death and despair...
Herald arts editor and Nick Cave superfan Linda Herrick names what she thinks are his best songs about love.
1. Push the Sky Away
(from Push the Sky Away, 2013)
Gorgeous, pulsating, subtle organ underpins Cave's tender, reflective baritone: "I was riding, I was riding home." No mention of the L word but it's got to be a love song.
2. And No More Shall We Part
(from No More Shall We Part, 2001)
"The contracts are drawn up, the ring is locked upon the finger..." Cave has always pondered the more sinister side of love, wrapping the potential for damage in a ballad that aches with longing.
3. West Country Girl
(The Boatman's Call, 1997)
"With a crooked smile and a heart-shaped face" ... Cave's ode to P.J. Harvey. It didn't end well. She filled him "with love, up to the brim". Then she dumped him.
4. The Good Son
(The Good Son, 1990)
Post-rehab Cave had fallen for and married Brazilian Viviane Carneiro, with whom he had a son. "I was quite happy," he later said of his time living in Brazil. The anthemic The Good Son is startlingly poignant.
5. Babe, I'm On Fire
(Nocturama, 2003)
The last album Bad Seed Blixa Bargeld played on, and Cave lyrically "on fire" in a mad roll-call of people from Bill Gates to the fox and the rabbit, shouting to the world he's in love. Not sure who with, this time.
6. Do You Love Me?
(Let Love In, 1994)
"Like I love you?" he demands, and the answer had better be right. A dream-team band (Mick Harvey, Bargeld, Rowland S. Howard) give an emphatic masterclass in stomping precision. "Wild bells rang in a wild sky," as Cave declared he'd love someone for ever. The spirit of the song is the antithesis of the sentimentality that wrecked tracks like Into My Arms.
7. From Her To Eternity
(From Her To Eternity, 1984)
The Bad Seeds' first album after the breakup of the glorious Birthday Party. From Her is an exciting, unsettling, crescending anthem to another doomed love, and the start of a wonderful band that has thrilled like no other.
8. Breathless
(Abbatoir Blues, 2004)
"Little white clouds like gambolling lambs." Cave's in full-flight poet mood as he reflects on how he is helpless, defenceless, breathless "without you". Very intimate, very sweet ... but not too much.
9. Henry Lee
(Murder Ballads, 1996)
Never did a song about a man getting lured by a girl, plugged with a little penknife and chucked in a well "till the flesh drops from your bones" look as sexy as Polly Harvey and Cave in the accompanying video, which screamed "body language". The look of love, as mentioned above, started out so sizzlingly but then the little girl lit down on Nick Cave.
10. Loverman
(Let Love In, 1994)
Who's a naughty boy, then? "There's a devil waiting outside your door" demanding "take off that dress I'm coming down I'm your loverman. Loverman!" Oh yes. Very dirty. Metallica gave it a shot in their 1998 album Garage Inc, which stripped the song of all its humour and still managed to be a joke.
Who: Nick Cave
What: 20,000 Days on Earth, at the New Zealand International Film Festival
Performing: December 6-7, Civic Theatre, Auckland; December 8-9, St James, Wellington. Tickets on sale today.
- TimeOut