As we're talking over the phone, you're in Zermatt, where Virgin's month-long Strive Challenge culminated in the "Strivers" climbing the Matterhorn. But your son Sam suffered altitude sickness and had to be taken off the mountain by rescue helicopter on the way back down. It must have been very worrying?
Fortunately, it actually wasn't alarming, because we didn't realise it was Sam that was in trouble, and then by the time we actually knew about it, he was safely at the bottom of the mountain. All was well.

And you're feeling proud?
The whole team are just magnificent. It's fantastic, what they've achieved over the last month. We had a big celebration with all the Strivers. Great kudos to them all. There's one lad who used to be a gang member – that's what the charity's all about. I'd almost be willing to bet that one day he'll be prime minister of England; he's just the most incredible lad. One day you must interview him. He's just an extraordinary man, a black kid in Brixton who's got out of being a gang leader to really wanting to make a difference in the world.

You've said that the challenge reminded you of some of your more hair-raising adventures.
Sam and Holly were brought up on their dad doing foolish things, and obviously there were a lot of boating trips and ballooning trips and other adventures. They were either going to take after my wife, who is the clear opposite of myself, or they were going to take after myself and be quite adventurous. And sadly, perhaps, they've taken after myself!

So you wouldn't call your children risk-averse?
No. We've done some wonderful things together. We've kited the Channel together, we've tried to break the transatlantic sailing record together, we've climbed Mont Blanc together. I think they will say that it's these sort of moments, like the last month, when we've strived, that most likely would be the moments they'd remember the most in their lives.

And what connects your life in business with your life in a balloon, as it were?
A lot of things about adventuring are not that dissimilar to being an entrepreneur. If you're an entrepreneur, you're trying to create things that have never been created before, you're trying to do it better than anybody else has done it, you're trying to make sure that you protect the downside, so that if it all goes wrong it's not going to bring everything else you've created crashing down. And if you're an adventurer, again you're trying to achieve things that haven't been achieved before, and again you're trying to protect the downside. And the downside can be your life.

Speaking of business, you've written a book about it, The Virgin Way. What's the idea behind it?
I've had almost 50 years being an entrepreneur and building companies. And so it's hopefully a helpful hand to young people who are setting up and trying to run businesses, or even working for businesses. Having said all that, I think the best way – and my publisher will kill me for this – of learning how to run a business is just to get on and do it and throw yourself into it, and learn through having to survive in the jungle.

And presumably have something people want?
If you can come up with an idea that makes people's lives better, you've just got to get on and create it. Virgin Airlines came about when I was trying to get from Puerto Rico to the Virgin Islands, and the airline decided to cancel the flight because they didn't have enough passengers. I was in my 20s, and I went to the back of the airport, hired a plane, borrowed a blackboard and jokingly wrote, "Virgin Airlines, $39 to the BVI" and I filled up my first plane. Out of personal frustration comes the best businesses. We're building a spaceship company because Nasa weren't interested in you or I going to space, they were interested in putting a few extraordinary astronauts into space. So I was frustrated waiting for the chance to go into space, and it wasn't going to happen unless we just went ahead and tried to do it ourselves.

Aha, space! So when are you going to get there?
I'm careful with my words! I'm a born optimist and have said on a couple of occasions that I thought that it would be on such and such a date and it's got delayed. And it is rocket science. I'm confident it won't be very long now.

And that's not the only event on the horizon. Early next year you're going to become a grandfather when your daughter Holly has twins?
[Sam's wife] Isabella's also pregnant, so we're actually going to have three grandchildren all within two weeks of each other.

Exciting times…
We've been prodding them a bit over the last 18 months, and we've got our wish. Holly and Isabella are best friends; they've got houses next to each other in Oxford and also in the Caribbean. The three kids will very much grow up together, so it's going to be great.

When you did the ice-bucket challenge, you nominated all 60,000 of your employees. That's a lot of people. Does it still take you aback, when you think of how small you started?
I appreciate my life enormously. I do definitely use the words fortunate and lucky a lot, because I have been extraordinarily fortunate and extraordinarily lucky, particularly with my adventuring. I've definitely gone through nine lives.

Are there things in your business life that you wish you'd done?
Most of my time's spent on the not-for-profits, and we run them just like businesses; some are doing really well, like businesses, and some could be doing better. We've got the Elders, who are trying to tackle conflict resolution issues; we've got the Carbon War Room, working hard on climate change issues; we've got the Oceanic Elders, who are trying to protect the species in the oceans; the B Team, which is business leaders trying to work on the environment; and the Global Commission on Drug Policy, which is trying to get governments to try to change their approach to the war on drugs, and treat it as a health problem not a criminal problem.

That's what interests me the most. We've got a wonderful team of people who are pushing Virgin into new areas, like cruise ships and inner-city hotels and other things. I'm interested in that but it's not my reason for being any more. I just find Virgin Unite, our foundation, and that work, just that much more interesting.

A lot of the book is quite old-fashioned: you champion listening, taking notes, forgiving people if they make mistakes – things that seem quite at odds with modern, cut-throat business.
I was lucky in my upbringing. If I ever gossiped or said anything negative about anybody, my parents would send me to the mirror. It taught me that looking in the mirror for five minutes at yourself is not very pleasant, and it taught me to look for the best in people, and to praise people rather than criticise people. We all love praise; and particularly if you're a leader, if you say something negative about somebody, the weight of that statement is going to be magnified many times just because you are the leader. Therefore it can be very damaging. And people know when they've done wrong, they don't need to be told they've done wrong. But they do need to be told when they've done right.

You're very frank about things that haven't gone right. You seem to regard them as a necessary part of the process?
I actually think, particularly in Britain, that people don't mind people who have tried things and failed and then try again until they succeed. In fact, if you always succeed first time, people might think you're a bit smug. The first time I crossed the Atlantic in a boat, the boat sank 100 miles from Britain, and we picked ourselves up and succeeded the next year. If we'd succeeded the first time round, people might have said, so what?

And in business?
When we took on Coca-Cola, we had a year in which we were really giving Coke and Pepsi a run for their money and we were very much the underdogs taking on the biggest giant in the world, and when they sent in their big tanks and to an extent crushed us, the public didn't think any the poorer of the Virgin brand for it. In fact, I would say the Virgin brand was enhanced by the battle.

So you don't regret it?
The key thing is never to do anything which discredits the brand, like ripping off the public or doing something which you'd feel uncomfortable reading about. If you're going to go down, go down fighting.

The Virgin Way: How to Listen, Learn, Lead and Laugh is published by Virgin Books, £20. Click here to buy it for £16 with free UK p&p