I remember the first one pound note I owned. I must have been eight or nine years old. We lived on a cul-de-sac in Dublin, and my friends and I would loiter at various corners of the road. A friend's older brother was with us that day, and when he was around he assumed leadership. We instinctively competed for his patronage. I remember pulling the note out from my pocket, carefully and surreptitiously, so that one third of it was showing. Finally, it caught his eye: “Hey! Lonergan's got a pound”. I was teased for the obviousness of my bid for attention, but only briefly: I had risen in his regard. After all, I had a pound.

Twenty years later I work for an investment bank in London. It is a world centred on money. We trade and advise clients for profit. Many colleagues obsess about how much they are paid, and how this compares to their peers. I care about how much I earn too, but mostly I enjoy my work. I am fascinated by why currency, bond and stock prices fluctuate. It is exciting and cerebral. Interaction is less personal the greater the number of participants. Markets connect a great many, so they are abstract and quantitative. But always human. Mood and perspective can swiftly change.

On rare occasions what I do gives me a glimpse into a dark future. And then I feel futile. Markets foresee problems, like an alarm that rings before the fire has started.