Paul Thomas Anderson: Young and breathless

Paul Thomas Anderson is as idiosyncratic as his movies (Boogie Nights, Magnolia and now Punch-Drunk Love). He tells Charlotte O'Sullivan about the woman of his dreams – and why he fell out with Burt Reynolds

When actresses talk about a director they've just worked with, they tend to say things like, "It was an honour. I feel so lucky..." When I call Emily Watson to ask about Paul Thomas Anderson, the word she reaches for is "bonkers". She's used to odd men, having worked with Lars von Trier on Breaking The Waves. "Lars was more crazy," she concedes. But don't let that fool you. The 33-year-old San Fernando Valley auteur is "quite screwed up".

Watching Anderson's movies – Hard Eight, Boogie Nights, Magnolia and now Punch-Drunk Love – you do feel you've entered a sort of Technicolor bedlam. Dense with mordant detail, punctuated by sing-songs that grow ever more hysterical, these films offer emotional roller-coaster rides that seem doomed to crash off the rails. Eye boggling and gut wrenching, they can also be contrived and exhausting. The first time I saw Punch-Drunk Love – a romance that teams Watson with the normally smackable comedian Adam Sandler – I emerged angry and disappointed; the second time, elated. Art house crowds like to work for their pleasure (the film won Anderson a best director award at Cannes); mainstream audiences are less keen. Boogie Nights was a surprise hit, Magnolia did less well. Very few people in America went to see Punch-Drunk Love.

Anderson, apparently, doesn't care. He's been doing interviews all day at the Dorchester, but still manages to come to the door with a grin. Skinny, pale and freckled, his hair sticks up like Alfalfa's in The Little Rascals; his voice, too, could belong to a seven-year-old. It metaphorically tugs at its grubby sleeves and looks up bashfully through the longest of eyelashes.

Anderson's main characters talk in just the same way – Boogie Nights' porn star Dirk Diggler; Magnolia's earnest LAPD cop, Jim Kurring; Punch-Drunk Love's Barry Egan, a sex-line-ringing, occasionally violent entrepreneur. These men might seem slow at first glance – even gormless – but all prove remarkable: superheroes whose special power is innocence. The difference is that while Dirk remains in his own, sealed world, protected and oppressed by his porn "family", Jim and Barry break free from their prisons to find love with a wonderful woman – in Barry's case, Watson's Lena. Some crucial part of their development may be arrested, but Anderson's child-men definitely have a future.

The director, in fact, says that Barry and Lena are going to be happy for ever and ever. I say I give them five years and he looks stricken. "No way, Barry's never going to have any problems, any more, for the rest of his life; everything's perfect now, for both of them. I wouldn't wanna see it not work out. I don't like it when it doesn't work out in the movies. I hate that."

I feel the need to remonstrate. What about a film like Chinatown? "Well that works out" he counters, blinking. But Faye Dunaway dies. "She seems like she wanted to die," he says cautiously. But her abusive father gets to keep the daughter! "OK," a cheery smile, "Chinatown is maybe the exception."

Just as you're getting used to the sweet talk, however, Anderson turns sharp. After telling me, for example, that he always gets along with his actors, he adds, "except for Burt Reynolds". Reynolds, Oscar nominated for his electric turn as a porn director in Boogie Nights, famously had doubts about the film's worth. Initially unwilling to publicise the project, he was cajoled into doing radio press with Anderson, only to become incensed because he felt Anderson was doing all the talking.

So why did things get so dicey with Burt? "Huh!", snorts Anderson, "let me count the ways..." He chuckles away to himself, becoming positively wheezy, then asks sternly: "Do you think you'd get along with Burt Reynolds, if you were directing a movie?" I say I've always had a soft spot for him, because he went out with Tammy Wynette. Anderson considers this. "How long did it last?" I shrug. "Do you think they really went out?" Good grief, so he thinks it was all just PR? "Uhuh," he nods, "uhuh," then lets out a mournful sigh.

But really, why didn't he like Reynolds? "Well, it could have been the pills [plagued by old injuries, Reynolds has a love/hate relationship with painkillers], could have been that whole attitude..." So he doesn't feel they were both to blame? "Nah, I don't think it was me. I think it was Burt."

At this point, Bumble Ward, Anderson's British agent, enters the room. "I'm talking about Burt Reynolds," says Anderson. "Oh God!" says Bumble. "Do you think it was me?" he asks waggishly, to which she replies, sensible as Mary Poppins, "Least said soonest mended, I'd say."

Back on track, Anderson returns to the friendly subject of actors he does like. He explains that he fell in love with Watson while watching her in Breaking The Waves. He adored Björk in Dancer in the Dark. He also talks about a long-term crush on the girl in an obscure, 1996 French film, called When The Cat's Away. I've seen it, and agree that Garance Clavel, with her long, straggly hair, saucer eyes, and air of frailty, is lovely. These child-women are the perfect counterparts to Anderson's child-men. They also bear an uncanny resemblance to Anderson's real-life girlfriend, confessional pop singer Fiona Apple.

What surprises me, I say, is that Punch-Drunk Love's Lena is such a different type. Anderson sits up in his seat. Lena's so mature, I continue, so sturdy, so trouble-free. "Keep talkin'," says Anderson grinning, "keep talkin'."

Well, I say, are these two types of women equally attractive to him or has he a preference? Anderson gulps. "Well, you can have a crush on more than one girl," he pouts, then bites his lip. "God, good question. I think I'm still figuring this one out". He bounces up and down. "You know what you make me wanna do?" he says, "Watch When The Cat's Away again! I know that I've changed a lot since I watched it first, but I'm sure when I watch it again I'll still have a crush on her. But you have no idea... how excellent..."

He leans forward with a squeak, fingers all of a jumble. "I'm gonna have to have a cigarette. I mean my mind is racing. I never think of things like that so much, or maybe I do..." He starts again. "I write this part for Emily [Watson], kind of like a dream girl, for Barry, which connects it to me... but if I don't know, if you're a boy, sometimes there's... but no, that's also a problem..." A long silence, while I muse over the fact that he still thinks of himself as a "boy". And wonder what sort of state his and Apple's relationship is in.

"I'm sorry," he says with a gasp. "I feel like I'm spinning out. There's so much going on in my mind right now."

He seems genuinely unravelled. Feeling slightly guilty, I note that trying to analyse yourself in an anonymous hotel room must be disconcerting. "Yeah," he agrees, brightening. "You have to go inside your own mind – you're forced to go inside – just to be distracted from how ugly the furniture is and how disgusting the lighting is."

"You know what," he says, leaping up, "there's a very easy solution to this. It's the lighting really." He crosses the room, turns off the main light, then heads off to the window and whips opens the net curtains. "The one day of sunshine that you have in London..." he mutters. "That's much better. Overhead lighting is not good – it's bad in the movies, it's bad in real life. But you get in an environment that you know you're a foreigner to and so you accept it. I mean these fucking hotel rooms. There's a James Bond junket down the way. Another for 8 Mile. You think, 'OK, this is what we do – here we go – we all go to work...' "

I don't think he likes to sound jaundiced. He quickly changes the subject to James Bond movies. But somehow, via Jane Seymour (he refuses to believe she was in Live and Let Die), we get back to When The Cat's Away. The heroine seemed so lonely, I say.

"I know, I know," he groans, instantly crestfallen. "It's so terrible. That scene where she..." his voice – to my astonishment – trembles, "Oh! when she makes out with the guy, and then the phone rings and he brushes her off and obviously it's his girlfriend calling." His breath catches again. "Oh god, that's heartbreaking."

Anderson looks beaten up; then the door opens and Bumble appears. He turns towards her, cow-eyed, and says "When The Cat's Away, Bumble..." She flashes an all-purpose smile, and tells me I've got time for one last question.

Flustered, I ask if he's really going to do a Boogie Nights 2? Anderson claps his hands. "Julianne Moore stripping again. All right!" Then, with perfect timing, "No. I would never want to do that." Does he have any firm ideas about future projects? A slow shake of the head. And that's fine, is it? A shrug. "No one will mind if I don't do anything." And the room goes quiet.

"Can I have a hug?" asks Anderson . He drags himself up from the sofa and moves like a zombie towards Bumble. "Are you OK?" she murmurs, before giving him a squeeze. "Yeah," he mumbles back, then says loudly: "I'm hungry."

Asked for an incident that sums up Anderson, Emily Watson (currently working on stage in New York) says that last week she returned home at midnight to find a package of Magnolia cupcakes on her doorstep. "He was always going on about these cakes... He'd remembered it was my birthday, and got a friend to hand-deliver them." She says Anderson is one of those people who doesn't need drugs. "He's on a permanent life high. He came to dinner with me and my husband once. Basically, if you give him sugar, he's on the ceiling."

She also says, right at the end, that she wants to work with Anderson again and that she finds him a "beautiful person". This is the kind of thing actresses say about directors. For once, I actually find it touching.

'Punch-Drunk Love' is released on 7 FebR