We started the season with updates of the ’71 car which was okay, but getting a bit old. At Kyalami I finished seventh in it, just two places behind my team-mate Ronnie Peterson and he was thought of as the big talent of F1 at that time. It was okay as a starting point but we badly needed the new car. Or so I thought. I think I first drove it in a test at Silverstone. It was shit. Really. It had no downforce, it understeered, it oversteered, it was slow down the straight and the gearchange was awful. It was like that from the first time I drove it to the last. No matter what changes is they made, it was the same. It was undriveable, I could do nothing with it.

We first ran it at Jarama. Ronnie qualified it in the midfield but I was last. I just could not make any sense out of it at all; it was chaotic to drive. It broke early in the race and I was glad to get out of it, but also very depressed.

At this stage Ronnie thought it wasn’t too bad, that it could perhaps come good. I told them what I thought of it and they just told me “Well, Ronnie doesn’t think it’s too bad” and quite obviously they listened to him rather than a novice like me.

We went to Monaco with the car, a place where Ronnie was King. He finished 11th and I was 16th. Then it soon became obvious to everyone how bad it was; even Ronnie was sliding down the field in it and he and Robin, I think, were beginning to realise that I’d been right all along.

For Belgium they stuck a Hewland gearbox in it, which made the change better, but the rest of the car was as bad as ever. The final straw, I think, was when Ronnie complained that a privateer in a DFV-engined F2 March passed him down the straight. By the next race we had the same thing: an F2 car with an F1 engine stuck in it. It wasn’t great but it was a lot better.

The main reason I didn’t lose confidence was that whenever we tested I’d do a time close to Ronnie’s, sometimes even quicker, and as he was one of the top guys I realised that I couldn’t be too bad. Also when we raced in F2 together I could be competitive with him. Ronnie was very supportive and helpful. We used to share a flat and we’d drive up to the factory in Bicester together and he would help and encourage me.

It was a disaster for me at that time. For Ronnie, who’d already made his reputation, it was okay. He could walk away from it and he joined Lotus. But for me it looked like the end. I couldn’t see how I could stay in F1, or how I could pay the money back.

Then March called me to Bicester and said they had the idea of running Chris Amon in one car and maybe me in the other for the next year and I didn’t have to bring any money. Maybe I could make it work, after all, I thought. Then, in November, very late after everyone had already done their deals, they called me there again and told me that the company was going bankrupt and they didn’t think there would be an F1 car for next year.

I remember very well I drove from the factory into Bicester and there was a stop sign where there were houses opposite; you had to turn left or right. I thought for one second I’ll drive into that house now and kill myself because there is no solution to pay the money back and I’ve failed completely in proving myself in F1. Thank God it was only a flash and I controlled it quickly. But part of that feeling was because of that 721X.

I sat down and calculated that if I got an office job, it was going to take me about 50 years to pay back the money. So I’d only be half-way through paying it back even today. All just for one season in that shit-box. Thankfully, I was able to persuade Louis Stanley to run me in a fourth car for BRM in 1973. But that, as they say, is another story.