My Way: David Windmill, of the Royal Zoological Society of Scotland, on how to succeed at work

'You need knowledge – and a genuine passion for nature'

David Windmill is the chief executive of the Royal Zoological Society of Scotland, where he is responsible for Edinburgh Zoo, Scotland's second-largest paid tourist attraction

What did you want to be as a child?

A doctor.

What did you realistically think you'd end up doing?

I realised that I wasn't bright enough to become a doctor, and that money was reasonably important, so I thought I'd go into business.

You studied biological sciences at the University of London – was it worth it?

Yes, because it's worth doing something you're interested in, not because you have to do it. At university, things became easier for me and I stayed on to do a PhD, using the kidneys of houseflies to look at how fluid moves around the body. Girls at parties would ask me what I did and when I said breed houseflies they took a few paces back. I didn't finish the PhD, I'm afraid; towards the end I realised I wasn't God's gift to academia so I joined a merchant bank in the City as a management trainee.

What happened next?

At the bank I learnt to be a manager, which is what I am now. I spent eight years developing and managing agricultural projects in Nigeria, Liberia and Sudan. But I didn't want to be an expat so I joined Booker plc, managing its salmon-farming operations on the west coast of Scotland and the Hebrides. I knew one end of a fish from the other and I had experience of managing commercial operations. When Booker bought Marine Harvest I became managing director of the world's second-largest aquaculture business.

How did you end up running a zoo?

Edinburgh Zoo had difficulties and I was in the right place at the right time.

Do you consider yourself successful?

In this job, yes.

What's the best decision you ever made?

Going abroad. Living and working abroad means that you meet a range of people who are from outside your culture, and you learn to sink or swim.

Have you fired anyone, and how difficult was it?

These things are never easy but I am paid by an organisation to manage it and to put it first.

Have you ever been fired?

I was made redundant from Marine Harvest and I didn't enjoy that.

What are your CV tips?

Make them short but not boring, put in a bit of colour, such as a passion or a hobby, but don't bang on about it.

Your interview tips?

Give generous answers but don't be afraid of silences.

What motivates you?

Seeing the impact of a decision process that I've been involved in.

How do I get to be where you are?

You need a degree, for example in conservation, and knowledge of what zoos do, which these days is conservation and education. You also needfinancial knowledge and experience, which means getting a qualification. Most of all, you need to have a passion for the natural world.