Graham Ward, executive coach and former co-head of pan-European equities at Goldman Sachs, explains how he came to quit banking.

Between 1988 and 2004 I worked at Goldman Sachs, rising through the ranks to become co-head of the European equities desk. After 19 years in the industry, everything should have been peachy – I co-led an incredible team of dedicated, high performing professionals and we'd just executed the biggest block trade in stock market history (a high-risk, high capital deal; the implications of failure would have meant a significant dent in the overall earnings of the bank).

As often happens, however, around the age of 40, some major life questions began to appear. The 70-hour week and its consequent strain on family life, my growing guilt at failing to contribute to broader society and the accumulation of wealth with no logical rationale began to nag at me. I was not living life, it was living me.

I'd harboured a private interest in psychology for some time. But my moment of revelation struck during a Goldman leadership offsite in Connecticut. In the dreamily bucolic setting I dropped my bombshell: I would shortly leave the bank to pursue a career in psychology. Luckily, the skilful intervention of facilitators steered me towards calmer seas – they convinced me I'd be better served by using my considerable business experience and people experience as a coach. They also persuaded me to tell the CEO of my intentions.

So it was on one dark December morning that I risked the 15 years of capital I'd built up at the bank and confided my aspiration in the chief exec (Wiet Pott, CEO of Goldman's equities in Europe). The outcome was astonishing – he persuaded me to stay with the bank and agreed to sponsor me through a degree in coaching at INSEAD. He also gave me a greenfield site in the form of career development for a division with close to 5,000 employees.

Hence, for three years I worked as an internal coach at Goldman Sachs, offering senior business leaders advice on performance enhancement, career progression and conflict resolution. My business credibility held me in good stead – the leadership office was deliberately positioned outside the fiefdoms and systems within the bank. It was also outside HR, whose involvement I knew would render me toothless and embroil me in bureaucracy.

Over those three years I coached a few hundred people. To coach someone is to share his or her inner world, hopes, fears, fantasies and aspirations for a period of time. My most frequent clients were senior women who had hit the so-called glass ceiling. Further exploration of this issue led me to discover certain inequalities that needed to be addressed. I tried to do this systematically and became regarded as some kind of uber-feminist – not ideal from the perspective of the rest of my client base.

However, my days as an internal coach at Goldman were numbered. After the business went public in 1999 it was left in the hands of a new breed of younger, hungrier executive. I was asked to return to the business, which I did, albeit half-heartedly. But my motivation to stay at the company that had done so much for me evaporated and, within a year, by mutual agreement, I left.

I dismissed my first inclination – to tout myself around the financial community in Scandinavia – and suppressed my predisposition to hyperactivity. After long walks in the woods with an ever-thinning but happier Labrador, I decided to set up a coaching consultancy.

I now run the consultancy, and teach at INSEAD, my alma mater. The question I'm most frequently asked is why I made the transition out of investment banking – and how I could trade a cutting-edge role for one that's seen as 'soft'. My answer is this: like parents taking pride when their child rides a bike for the first time, coaches get their rewards vicariously, from helping clients do their jobs better. At their most effective, coaches can be the butterflies whose wings stir ripples that can, over time, create hurricanes of change. And if that's not rewarding, what is?

• A version of this text originally appeared in 'Coach and Couch, The Psychology of Making Better Leaders,' by INSEAD Business Press.