MY MISTAKE happened in 1987 when I was working at a relatively junior level in investment banking. I had just about enough money to buy a house, but it was completely obvious to me that it was a really stupid thing to do. I knew from my job that the housing market was thoroughly overblown.
My parents said "Go on, you must buy". I was 26, and they believed what they were saying. They had done well in property and had been through the whole inflation thing in the 1970s. They were terrified I'd never be able to afford it if I didn't act then.
At the same time, I was listening to commentators who said the market was going to go down, but against my better judgment, I gave in. It was 20 per cent humility: when you're young you can be priggish and fail to realise that you might not be right. I was trying to balance that by incorporating some tribal wisdom and not just trusting my own instincts.
I bought an incredibly poky, nasty little flat in Notting Hill, with a nearly 100 per cent mortgage. Within a year, it was worth pounds 25,000 less than I had paid for it. I had to sit on this piece of negative equity for two years, and then was able to sell it a year later.
What I learnt was that if you don't act on your own professional knowledge, and instead take other people's opinions and act on those, the feeling of having got it wrong is 10 times worse than if you had made a bad decision on your own. It made me realise I should trust my own decision-making ability.
There was one positive thing. At the time, the American banks were paying mega-salaries: I was working for a European bank and regarded American banks as very challenging. Being in that situation with my home suddenly made me realise that you don't have many high-earning years, and there's nothing more effective than a big lump of negative equity to make you want to make hay while the sun shines. So I moved to Lehman Brothers and spent four years there, which was a good shift and a dynamic environment.