One day at school in France, when I was about 11, I finished early and when I reached my home I realised I had forgotten my key. I lived on the seventh floor and decided to climb the building. It was concrete and there were big holds, plus balconies, so it was kind of easy.
The most difficult climb I have done was the Sears building in Chicago, which at that time was the biggest building in the world. It's the kind of building – flat, slippery, 443m (1453ft) tall – that is really tough.
My worst injury was on September 29, 1982. I fell head first from about 15 metres and landed on my wrists on some stones. Both wrists were completely smashed, then my elbows, my pelvis, my knee and my skull. I have had many more injuries, but that was the worst one. I don't wear protective clothing like a helmet because it would be against my spirit; I like freedom.
I don't force myself to do things I don't want to do. This is very much my philosophy. When I climb, I am focused on my target. Getting to the top is a great feeling because there is a lot of fear before an ascent; then when I start climbing it is fine because I am in fighting mode so I don't think about fear any more. But once I reach the top, it's a bit like if I was reborn. For a while, you put your life at risk – you know you are between life and death – then, once you reach the top, you can enjoy. It's like there's a life ahead. It's an interesting feeling.
I am kind of addicted to it, because even now, aged 50, I need to do that. I think that as long as I am alive, I will be doing that kind of stuff. I feel I need the thrill of it to feel alive.
Some buildings are not possible; those I think should be possible, I go to the location and then if it's OK I do it, most of the time illegally. There's an injunction on me climbing the Shard in London. If I am seen in the perimeter around the Shard, they are allowed to arrest me. I think it's stupid because I have never planned to do this ascent illegally. I am just trying to get approval to do it officially. I would like to do it because the shape is right, the architecture is interesting and it's 310m (1017ft) high so not ridiculous.
A 200m (656ft) building takes 45 minutes on average. Something like Petronas [450m/1476ft-high twin towers in Kuala Lumpur] took a bit more than 1.5 hours; Burj Khalifa in Dubai, 830m/2724ft [the world's tallest building], took six hours.
I did the Eiffel Tower twice. The first time was interesting because it was -15C and I did it on New Year's Eve 1996, so when I was at the top it was 1997. The cops were nice; the security people were not nice. Cops are a bit more intelligent with a much better understanding. They can judge whether it is a crime or whether it's a misdemeanour charge. Most of them like to get autographs.
When I climb, I am calm, but other than that I am quite a nervous person, in the sense that I can be annoyed by people. I hate rules, that's the problem, and our world is surrounded by rules on everything.
There are plenty of other buildings I'd like to climb – in China, Argentina, Chile. It's just a matter of time.
Alain Robert is giving a talk at the Edinburgh International Climbing Arena on Friday at 8pm. For tickets (£18) call 0131 333 6333 or go to EICA reception. Visit eica-ratho.co.uk.