His publishers took him at his word, and included his intention in print in his bestselling book. "I remember riding around the Wicklow mountains as a child [his father is the Wicklow-based film director John Boorman] with my best friend and we would dream about doing the Dakar rally. But it was always just a dream, " says Boorman.

The dream soon became a reality when Boorman found himself committed to taking part in the most extreme and dangerous bike race in the world, racing 700 to 800 kilometres a day through some of the harshest terrain in the world, including the Sahara desert.

Boorman started testing publishers and TV producers' interest in the project. "I started asking people would they be interested and half-hoping they'd say no so I could say, 'Oh well, I gave it a go.' But they all said yes and that was kind of nice because I've always been attached with Ewan on this project and to do this one by myself was a bit scary."

Boorman spent a year training with Dakar veteran Simon Pavey. "Simon would tell me it's about having ability on a motorbike; you've got to be a good, competent off-road rider, but then he said, as important as that is, it's also about what goes on in your head. You have to do these 15 days of 700 to 800 kilometres a day. It's like riding a motorbike from London to Edinburgh everyday, off-road. If you're a little bit late you're out, if you break down, you have to fix yourself up or you're out. Once you get into Africa and start riding it really is about that because a hundred times a day in your head you think of a perfectly good reason to give up, but somehow you manage to block that out."

There were moments of grace says Boorman, but most of the time you were too busy concentrating to get a chance to admire the surroundings. "You concentrate so much on your navigation and navigation was such a problem for me, especially being dyslexic, but then you have these moments where everything is working. You've got a bit of clear space . . . it very much depended on your visibility as well because most of the time you're just in a cloud of dust . . . but there were moments when you look through it and you do get these incredible feelings of you're so small and you're so privileged to drive through these beautiful places and then of course you see someone cartwheel in front of you really badly and you're thinking, 'Oh my god, the bike's coming right for me.'

That brings you right back to reality."

After his year of training, Boorman found himself on the start line of the Dakar rally in Lisbon. "I've always wanted to do it and it was quite a profound moment when on day four of the rally everything was going really well and I remember realising I was doing the Dakar rally and I couldn't believe it. It was quite an overwhelming thing."

Things stopped going so well when Boorman broke both of his hands in a disastrous fall from his bike, which put an end to the race for him. "My first thoughts were for the book and the TV. I thought, 'What the f**k is going to happen now?'" Despite very serious injuries, he had to ride on for hundreds of kilometres until he reached the next race checkpoint. "My hands were in pain. When I looked down at my thumb and it was pointing in the wrong direction I thought, 'This is just not right, I can barely hold on.' And then everything started to implode. It felt like a building collapsing inside my head . . . the book people, the TV people, the DVD people, the BMW people who had supported me so much for this project. And I just felt I'd let everybody down. It was the most awful 450 kilometres of my life."

When he finally got to the checkpoint, his gloves had to be cut off his hands as they had swollen so much. "When they cut the gloves off me Simon Pavey, who is this hardened racer, just went, 'Oh f**k', and I knew then I was out."

Boorman says amidst the acute disappointment, there was also a sense of relief, "because of the pressure you're under each day to finish". His wife, Olly, was also relieved. "When I rang her I could feel the sense of relief. Firstly, she whooped with joy and then said that's terrible. I hadn't realised how much pressure I had put my wife under. And she is such a star for me. We've been together for 20 years and I'm so totally in love with her."

While Boorman has had some success acting in films, he says motorbikes are his true love and he enjoys the work he is doing now. "It combines a lot of things I like doing. I love television, editing, creating projects, doing them, so for me it ticks a lot of boxes. I'd had a lot of successes as a child actor and up until I was about 23 years old I was always working and enjoyed working. Then things sort of petered off.

Maybe the film choices weren't quite right. I started having children and I became slightly less interested in films and more interested in my family."

He says he owes a lot to his friend Ewan McGregor. "We started talking about this idea and originally we were just going to do it ourselves but it was going to be impossible to take that sort of time off without money. Then someone mentioned about the book and we thought that's a good idea.

Because we had so little time and so much to do we thought, 'Let's do the book and TV series so we can get someone to do all the f**king crap for us, the visas and admin, '" he says laughing. "People now take me seriously. I'm so enjoying this.

I almost don't want to go back to acting. I'm really quite happy where I am."

Boorman still rides motorbikes everyday. I wonder did his experiences in the Dakar rally change him. "I think everybody's character stays the same, a leopard never changes its spots, but you learn from experiences like this, you become more aware of your surroundings. I certainly appreciate things more. I certainly appreciate my wife and family much more. I certainly appreciate life much more."

'Race To Dakar' by Charley Boorman is out now, published by Time Warner books