A 1,000m sheer rock face he can handle, but how does the free soloist feel about the comforts of home? .

Mr Alex Honnold has extraordinary hands. The fingers and palms on which his life depends as he grips tiny divots in a sheer rock face are, for one thing, enormous – Mickey Mouse gloves, if Mickey Mouse had both the strength of Hercules and the dexterity of a watchmaker. As he speaks, Mr Honnold sometimes cradles them as if they are both incredibly valuable and slightly heavy, which of course they are. His eyes, too, are outsized, as if drawn by a cartoonist to communicate preternatural focus and observational skills – skills that he’s been putting to use while wandering around in New York City where we meet.

“There are so many things that I see, and I’m like, ‘This is just not the way the world should be,’” he says. “I would love to reshape the city in a slightly different way. It could be so beautiful if transit were all electric, if you didn’t have so much noise or pollution. If I was born in New York, I feel like I would’ve taken a completely different path, but would probably have a similar personal drive.”

That drive, and, even more, the superhuman accomplishments to which it has led him, are the subject of the thrilling new film Free Solo, which documents his hand-over-foot climb, with no rope (ie, “free soloing”), the 1,000m sheer face of El Capitan in Yosemite. “The perfect rock face,” he calls it. “The most beautiful monolith on earth.” If Free Solo were a Marvel movie, the conflict it presents between the protagonist’s calling, his ambition to do something heroic, supernatural even, and the mundane concerns of existence (in this case, represented by Mr Honnold’s girlfriend, Ms Sanni McCandless, who rightly fears for his life) might seem a bit rote. Here, it is gutting, terrifying. Of course you want him to do what it takes to complete this extraordinary mission, and yet, please, God, no don’t! During one contentious scene in the film, when the couple take possession of their new house in Las Vegas, Mr Honnold, who, until recently spent six months of the year on the road, living in a Dodge Ram ProMaster, bristles at the creature comforts on offer. “She just wants to be cosy and happy,” he tells the filmmakers. “Nothing good ever came of being cosy and comfortable.” Which, he now says, is slightly overstating it.

Mr Honnold, 33, was born and raised in Sacramento and started climbing early in life with his father, whom he describes in the film as emotionally distant. In his adolescence, he says, Mr Honnold had to teach himself how to hug, because he’d never done it before. But even in his adopted hometown of Sin City, the American capital of decadence, Mr Honnold says he doesn’t rate his austere life path as better than anyone else’s – not exactly. Although, “having more interaction with death certainly makes you lead a more intentional life, maybe,” he says. “Makes you a little more mindful of your choices, how you spend your time. It probably makes me a lot less stressed in life.”

To wit, there is a wonderful sequence in the film in which Mr Honnold gets an MRI to see if his brain – specifically the amygdala, the centre of fear and/or threat response and interpretation – is in some way abnormal. Spoiler alert: the guy who relaxes by standing on a ledge as wide as your tie many thousands of feet from the treetops below him requires a great deal more stimulus to his amygdala to generate anything at all resembling fear, or even stress. “I think about that all the time in airports,” he says, “because I have to travel quite a bit, and you see people who are stressing at the airport, like, ‘What if I miss my flight?’ Dude, who cares. You’re not going to die. You’re going to get on the next flight. Your life is not going to change if you wind up six hours late.”

But if this is what he thinks about the humdrum concerns that so plague the rest of us down here, in the world, up there, scrambling up a mountain, Mr Honnold says he doesn’t think about anything at all. “Nothing – I’m just executing. Except for on the easy train where I’m thinking, ‘beautiful day,’ or whatever, enjoying the view and the experience. There’s a majesty to being up on the wall.”

And there is a thrilling majesty to the feat at the heart of this film, in the middle of which we seem to gain insight into Mr Honnold’s mentality. During a training session in Morocco for the buildup to his attempt, Mr Honnold professes an affinity for what he calls warrior mentality – the extraordinary focus and sacrifice required by samurai. The severity of which makes you burst with wanting to chill the guy out, buy him a burger and show him trash TV, but, good news: “I’d been binge-watching Spartacus,” he says, laughing. “I don’t think of myself as a warrior, per se. But at the time, I was just way into this show. It’s like Gladiator: violence, nudity, pretty classic TV, but kind of well done. I watched four seasons while we were in Morocco training, and it made me think of free soloing as gladiatorial – the new entertainment for the masses, blood sport. Because what makes free soloing interesting is it’s life or death. There are real consequences. Normal life is so removed from that. In normal life you’re never facing real consequences of, ‘I could die doing this.’”

The consequences in the Manhattan climbing gym, where Mr Honnold spends the night of the film premiere, are slightly less dire. Not that he’s going soft. Since free soloing El Cap, he has already ticked off a few more accomplishments on his climbing goals list, including setting the speed record on the same mountain (under two hours). But he’s still slightly unsure  how even to classify his great free solo endeavour. “I think in some ways the physical side is harder for me. I’m not physically gifted in the way that some professional athletes are just freakishly stronger than everybody else, so I think that I maybe value the physical side more. That’s what I have to work hard for. Whereas the mental side of it has always sort of come naturally, that’s kind of easy for me. I take that for granted; that’s trivial.”

Mr Honnold lays his hands on the table in front of him. Where his climb fits, scale-wise, among other human accomplishments, he hesitates to say. “I’d always built up soloing El Cap as the pinnacle of all climbing,” he says. “Like this would be the most ultimate thing ever done. I put it on this pedestal, like, ‘this represents everything.’ Then, once you work towards it and actually do it, it becomes much more normal. I made it manageable and then I managed it. So it’s a lot harder for me to say it’s the most impressive thing ever done, because I did it. But I still look at the wall and I’m like, ‘That is the most inspiring wall on earth.’ It doesn’t look any smaller, it doesn’t look any easier. You’re like, ‘Shit, that’s a big wall.’”

Free Solo is out on 14 December

Mr Alex Honnold wears The North Face