Bear Grylls admits he's not so invicincible afterall: 'I struggle with groups of people that I don't know'
He's not about to hang up his adventurer hat just yet, but Bear Grylls is happy to admit that parenthood and age have brought about a new sense of fragility.
As his latest novel is published, he tells Hannah Stephenson why, more than ever, it's all about the balance
His more famous exploits include drinking his own urine, eating grotesque grubs and sheltering inside a dead animal's carcass.
However, there's more to Bear Grylls than meets the eye. After years of adventure, both in and out of the TV spotlight, more injuries than he cares to remember (including a broken back which shattered his military career), conquering Everest and toughening up celebrities and ordinary folk in extreme environments, Grylls reckons he's not as brave as he used to be.
"I get more and more full of fear as life goes on," the Eton-educated ex-SAS soldier and Chief Scout confesses. "I wish it wasn't like that. I struggle with jumping out of planes after breaking my back, I struggle with groups of people that I don't know. I struggle with self-belief a lot of the time, and that battle becomes a harder one to win as the years go on.
"There's such a weight of expectation that you're going to be great at this or great at that, and you don't always feel that you have that mental strength to keep going. But I've learned that that's OK. Just give your all. Sometimes it works and sometimes it doesn't.
"I wish I could tell you you're looking at the invincible hero, but that just wouldn't be truthful."
Despite these claims, he's as busy as ever, currently in training with members of Cirque du Soleil for his first live arena tour due to start in October - an acrobatic adventure show called Endeavour, featuring 3D live mapping, transforming each arena into jungle, mountain, space or underwater scenes, as he celebrates some of the greatest feats of human endeavour through the ages.
But today, we're here to discuss a safer strand of his career, his latest novel Burning Angels, the second in a trilogy featuring ex-SAS hero Will Jaeger.
"Will Jaeger is a much cooler, fitter, stronger, nicer, more talented, better looking character than myself," he says, chuckling.
In this episode, Jaeger tackles germ warfare, a jungle island overrun by rabid primates, conservation and poaching, illegal arms dealing and a hunt for his lost wife and son.
"The whole premise of all three books is inspired by what my grandfather (Ted Grylls) was trying to do," he says.
Brigadier Ted Grylls was the commanding officer of Britain's elite T-Force unit, tasked with capturing Nazi scientists after the D-Day landings and spiriting them away to the West to stop their knowledge falling into the hands of the Soviets.
The novel is an action-packed page-turner, but not totally written by Grylls himself - Damien Lewis, former-war-reporter-turned-thriller-writer, is co-author.
"We've worked together really closely on both of these," Grylls admits. "He does a lot of the research and he'll write his draft and I'll rewrite it."
It's amazing he's been able to fit the book into his packed schedule, although having his ITV show Mission Survive axed after the second series freed up some time.
"A big part of me was really sad, because I loved Mission Survive, I love the values that it stands for and what it brought out of people. But do you know what? You've got to have the failures, I really don't mind. I've had so many shows not work.
"I don't like the word failure," Grylls adds. "I always think everything's a stepping stone to get where you want to go.
"We've just commissioned another series for ITV, based on the one-on-one Hollywood guests we do for Running Wild [Barack Obama famously joined him on an adventure for that one]."
So are his shows risky or reckless? His recent Channel 4 series The Island saw contestant Patrick Dauncey fall 30ft off a cliff. He survived, but it was a close shave.
Are programme-makers being pushed towards recklessness to boost ratings?
Grylls points out that he owns all his own TV shows (through his production company), so no-one ever pushes him to do more treacherous stuff.
"We are in a really dangerous arena. You've got people's lives in your hands. That's why we only have producers who are our team. We have a very clear value of: always be safe, never chase the ratings."
He was probably more reckless in the early days, he admits.
"The crew used to say, 'You used to be 120% reckless and now you're 70% reckless'. I see that as a positive thing. And it's definitely changed with having children. It makes you get smarter.
"It takes so little for something to go wrong, and it only needs to go wrong once. So we have no egos, plan well, do it smart and get it right."
Family - Grylls has three sons with wife of 16 years, Shara - has altered the limits as to what he'll personally take on, too.
"It's about a balance, listening to that quiet voice inside, planning well and working with a good team, but once you commit to it, just go for it."
Shara has lived with Grylls' penchant for dangerous challenges ever since they met.
"I was still in the Army when we first got together. I initially built a life through all the expeditions and then through the TV stuff, and she quietly trusts me to make good decisions and always come back in one piece.
"Sometimes it goes wrong and I come back injured, but on the whole, we are trying to progressively get wiser and smarter in what we do. We never stop learning, we never get complacent. You can't take your eye off the ball."
He says he's become adept at slotting back into family life - on their houseboat in London and their island in North Wales - when he returns from his adventures.
"You have touch-and-go experiences and then you're back in everyday life doing the school runs and homework. I like that. It keeps everyone grounded. I take lots of time off and always try to keep the family first, but it's always a dance."
His boys, he says, are smarter than he is, and also love adventure.
"They love the outdoors and being part of my work when they can. We take them climbing. Adventure is part of everyday life. They love the mountains. I take them paragliding and they love that."
At 42, Grylls says he has to work much harder these days to keep fit.
"The thing is, I don't want to reach the end of my life with a perfectly preserved body. I want to arrive covered in scars, screaming, 'Yahoo! I've arrived!'
"I should have died a zillion times but I'm still alive and I'm lucky to be a survivor," says Grylls. "I hope to still be doing it when I'm 65."
:: Burning Angels by Bear Grylls is published by Orion, priced £18.99. Available now