I never really thought I would get a chance to race until I was asked to do Bahrain in 2005 when Juan Pablo was injured. Alex didn't fit – the car was built around Kimi and Juan Pablo, and he had a problem with a fire extinguisher bottle that was touching his elbow, so they had to redesign it. So I got the chance.

Actually that race was pretty good for me. Don't forget that it was the qualifying system where there were two sessions, and there was an order of going out on Saturday, and if you hadn't done the previous race, you had to go first. So I had to qualify on a green track. But I still outqualified Kimi, I was eighth and he was a place behind. And then in the race I finished fifth and I did the fastest lap. 

I think after that that the perception of me inside the team changed a bit, and that's why in 2006 I had the opportunity to substitute for Juan Pablo after he left. It was the first year of the V8s, and the Mercedes was down on power. The races where we were most competitive were Monaco and Hungary, which weren’t very power-dependent. But the car was really nice, and I think I did quite well.

Read 'McLaren & Me: Pedro de la Rosa Part I' here.

Second place in Hungary was fantastic, obviously. I sometimes joke with the engineers, because we could have won that race. There was a safety car when Kimi crashed, and we had just come into the pits. They filled me with fuel to the end, and then it stopped raining, the track dried out, and I needed to change back to dry tyres.

I already had the fuel for the whole stint. And Jenson was nowhere with the Honda, and basically with the Safety Car he got back into the hunt, and he won. But we were on the podium, it was a fantastic achievement, and no one can take that away from us.

I regret that the team only confirmed that I would race during the week of each Grand Prix, so it was race-by-race. It was a time when Lewis was leading in GP2, and there were a lot of rumours that he would jump into my seat. I didn't like this situation. At the end of the day you do your best for the team, and at one point I had too much pressure to deliver, otherwise I felt I wouldn't be in the car for the next race. I think that I was over-driving a bit, because I thought if I didn't do a good job, Lewis would jump into the car. Finally I made it to Brazil, the last race, but it could have been a bit better.

When Lewis got the seat in 2007 I wasn't disappointed because I knew that could happen at any time during 2006. I understood, he was young, he was GP2 champion, he'd impressed everyone. That's life. Also Fernando was his team mate, so I realised that I had no chance.

My biggest disappointment came in 2008. Until late 2007, when Fernando left the team, there was a very strong chance that I would partner Lewis. And then the team took Heikki Kovalainen at the last second, and that really caught me by surprise. It was a low point in my career. I actually thought I had the drive. I even had my hair very short for Ron, but that didn't work!

However, the end of 2008 was one of the highlights of my career at McLaren. After the disappointment of 2007, when we lost the championship by one point, it was fantastic to see Lewis winning in such a dramatic finish to the season in Brazil. It was an incredible moment. I felt in a way that I was driving the car. I commentated on that race for Spanish TV, and I didn't speak on that last lap, because I was too nervous!

I was grateful that the team let me go racing in 2010. I had a contract with McLaren and I asked if I could go to Sauber, as I had the opportunity. And they opened the door for me. It was the era when the test driver was becoming less important, because the test days were being limited, and the race drivers wanted to do those days.

I think that McLaren saw the value of having someone who would become a race driver for a year or two, while having the possibility of having him back. It would be more useful for them. They could have blocked me, and they didn't. If they had said, 'Pedro stay here,' I would have stayed. I was very loyal to them, and they were loyal to me. We were very open.

And actually I did come back in 2011. But by then, the number of days was becoming more and more limited, and that's when the simulator started to become even more important. At the end of the season I told Ron that I was leaving for HRT. I don't think he even knew that team existed!

I am very proud of having stayed at McLaren for so long, and of being able to work with such fantastic mechanics and engineers. You always learn something from great drivers, like Fernando, Lewis, Kimi, Juan Pablo and DC. And also Alex – I learned a lot from him, and now he's a great friend, and someone I really respect.

I have fantastic memories of my time there. Thinking about the fact that I didn't get the drive in 2008, or that in 2005 I was replaced by Alex after Bahrain for the next race at Imola, there were moments when I was really angry, obviously!

But now looking back, I have no problem with it, and I'm very relaxed about things.  All-in-all I can only say 'Thank you' to McLaren. I am a much more complete racing driver now, and more complete person, than I was in 2003.