John Hawkes: 'To be a good actor, I need to be invisible'

If you haven't heard of John Hawkes, or don't recognise him from the photo, that's the way he likes it. He values anonymity in a way that is – how to put this delicately? – inconvenient, for someone who happens to be the leading man in a film that's this year's Little Miss Sunshine, or Eternal Sunshine of the Spotless Mind: the feelgood festival hit that is set to bring home a decent haul this awards season.

The film is The Sessions and it's just another everyday Hollywood love story involving a man, a woman… and an iron lung. It's based on the true life of Mark O'Brien, who was left paralysed by polio as a child and who is only able to turn his head by 90 degrees. And who, at the age of 38, decides he wants to lose his virginity. He hires a sexual surrogate (played by Helen Hunt) – someone who has sex with clients for therapeutic purposes, in case you're wondering – and goes at it, sharing the journey with his Catholic priest (William H Macy), a reluctant voyeur to the proceedings. ("Is it fornication?" O'Brien asks him at one point. "I have a feeling that God is going to give you a free pass on this one," he says. "Go for it.")

The film was a sensation at last year's Sundance where it won the audience award and a special jury prize, and Hawkes and Hunt are both up for Golden Globes tonight. (Hunt is also nominated for an Oscar and a Bafta.) Awards organisations have tended to be kind to movies featuring able-bodied actors playing disabled characters. But this film is far better than that might lead you to suspect. The first working title was "Gimp". On-set, it became "Fuck me, I can't move", and it's blacker and more comic than most awards-fodder; a funny, tender, humane, moving film that had half the audience at the press screening I attended weeping surreptitiously into their notepads.

It's a strong ensemble cast but Hawkes's performance is a tour de force. He plays O'Brien as a man with an acute sense of the inherent comedy of his situation, as well as its sadness, and while he isn't a method actor – he had no formal training – and didn't, he says, have the "luxury" of months of preparation, it's a hugely impressive performance. Mostly, though, in spite of O'Brien's physical limitations, rather than because of them. ("I understand you're able to have an erection," Cheryl, the sex surrogate says at one point. "Not by choice," says O'Brien.)

He spends the entire film trapped on a gurney, marooned in his iron lung or motionless on a bed. Hawkes used a device that he came to call his "torture ball" to help mimic the curvature of the spine that O'Brien suffered – but it's not a Daniel Day-Lewis/My Left Foot-type performance. It's much quieter, less showy. Like Hawkes himself.

He grew up in the midwest, and even in a swanky London hotel, with an Oscar nomination to his name – best supporting actor in 2011 for Winter's Bone - he doesn't come across as the big movie star. Not any sort of movie star, in fact. I've met Hollyoaks actors with more swagger. He's slight, reserved and looks much younger than his 53 years.

Like most of his work, The Sessions is an indie film. It was made for less than $1m, much of it raised in $5,000 and $10,000 donations from friends and supporters. And the writer-director, Australian Ben Lewin, was barely known. A director of mostly commercials, Lewin last made a feature film – Paperback Romance – 18 years previously. And even that wasn't very good. "I wasn't blown away by it," says Hawkes.

Hawkes didn't know it until he met him, but Lewin was also left disabled as a child by polio, though not to the same degree (he can walk with crutches). Does he think Lewin's personal history brought something else to the film?

"A bit. But the movie is bigger than disability. Ben seemed uniquely qualified to tell the story in that way But it wasn't important to the success of the film that Ben was disabled. I don't think of him as disabled. I think of him as an amazing, funny, wonderful person who happens to walk on crutches."

Hawkes has spoken most of this to the carpet. He's not so much publicity-shy as publicity-phobic. Eventually, I tell him "You seem very… uncomfortable talking to me." He finally turns to look at me. "Uncomfortable? No, not really." But you can't even look at me, I say. "It's my first interview of the day. And I've done a lot of them. And no offence, but I'd rather be a mystery to the world, and it becomes less and less possible. You know that every interview you do, more stuff comes out, or you're misquoted, or things are taken out of context. I'm not saying that will happen here but it seems to happen a great deal."

It's not that I don't feel sympathy for Hawkes. He is that highly unusual beast: a talented actor who has won awards and acclaim yet has hung on to his life as a private person. He has quietly but steadily made a name for himself, culminating in that Oscar nomination for his role as Teardrop, the meth addict in Winter's Bone, another low-budget indie. It may have taken him 30 years to get here but it's now the third year in a row that he's taken a hit film to Sundance. (After Winter's Bone in 2010, came 2011's Martha Marcy May Marlene in which he played the leader of a cult.) His speciality has been offbeat creeps and weirdos, though he says he's actually played every sort of character – it's just been the creeps that have drawn the attention.

Now, with all the buzz around The Sessions, this might be about to change. "It's a good sign that the work you are doing is connecting with people. But everything that goes with [a film's success] makes me a little nervous. I don't want it to seem like I'm horribly burdened by it all. I'm incredibly lucky. But I lament the loss of mystery. Because I cannot be as effective in my work when I'm the centre of attention.

"If I can't be invisible in a group of people and observe the behaviour around me and translate that into the roles I play, I won't be as good an actor. If somebody rents Winter's Bone and doesn't know who I am, that's probably a satisfying experience for them. If I've done six talk shows that week and they rent it, and they say, 'Oh, that's the guy I saw on the talk show last night" then it's going to be a very different experience for them. It's been a boon to be unknown because people are more apt to believe you, and that's disappearing for me."

You can see his point. Hawkes has spent his whole life not being a movie star, and the idea that he might suddenly become one has unnerved him to the point where he'd rather talk to the carpet than another journalist.

Born in Minnesota, and raised on a farm – which his father lost in the 80s recession – Hawkes has a deeply unpretentious, un-Hollywood streak running through him. For a 53-year-old, there's a strange innocence that has survived decades of the movie industry.

The most tangible consequence of his recent success has been the quality of the scripts he's been sent. He suddenly found himself with a huge choice, from which he chose the smallest film with the lowest budget: The Sessions. Did he enjoy the perversity of that?

"Sort of. I have a very understanding agent and manager and lawyer. But they see the big picture, as I do, that a career is better built on projects that you believe in, as opposed to trying just to make money where you can. I don't need much money. I've never owned a new car. I've only ever bought my mother a house. I don't own one myself, I've always rented. I've never had an assistant. I have low overheads so that I can afford to do projects that don't pay a lot. And I have the freedom that way to do what I like to do."

He has a cousin, with whom he lives in what he calls "the nicest house I've ever lived in but it's nothing fancy", and they hang out together, play music, "go and listen to music".

It's not just that he doesn't tweet or use Facebook – he doesn't even have email. After leaving Minnesota he went to Austin, Texas, and became part of what he calls "the post-punk scene" (he played in a band called Meat Joy) and that spirit has never really left him.

I ask what it was that stood out about The Sessions script?

"Well, certainly you read a lot of scripts about guys living in iron lungs who want to lose their virginity. I read one of those every week but this was the best of those."

This feels like something of a triumph. Because part of what Hawkes brings to the role of Mark O'Brien is a gentle, intelligent humour and there it is… a joke!

But, then, he seems genuinely to enjoy engaging with people who engage with his work. And this is a breakthrough role for him. He's the leading man, rather than the weird uncle, and he's a fully rounded character whom people can't help warming to. "I've had people come up to me and say I've related more to that horizontal guy than I've related to any character in a film for a long time.

"This is a guy who can only move his head 90 degrees and has a life very different from most of our own. But the idea of wanting to connect to human beings and to want to touch and be touched and to have a full range of human experience, I think these are things we can all relate to."

What's so unusual about the film is that it's about love, connection and human intimacy but it's not in any sense a Hollywood romance.

"I think so. I'm no expert. I've never been married so I'm maybe the wrong guy to talk about it…"

And then he apologises. Quite genuinely. "Forgive me if I'm come off as distant but I can't be honest about how I feel. Every once in a while I can, perhaps. But I've probably already said too much. Forgive me if it feels like pulling teeth. I've actually been more forthcoming with you than I have with most."

So, yes, I do forgive him. I just rather hope for his sake that he doesn't do anything foolish. Like win a Golden Globe.

The Sessions opens at UK cinemas on Friday