10/10/2013 10:47 BST | Updated 23/01/2014 18:58 GMT

How I Became...

Mine is a lesson, to coin a phrase, about being a square peg in a round hole - a person whose character makes them unsuitable for the job they are in. Here is what I did about it and how I ended up in a better place.

Having worked incredibly hard at school to achieve (against the odds, my teachers might have said!), straight 'A's' at A level and then attaining a first class English degree at University, I was pretty proud of myself for finding, very quickly, employment within a blue chip company in London.

Growing up, I had endeavoured to please and to impress everyone around me by doing what I thought was right and, ultimately, doing what I thought I wanted.

I had ticked every box at school and University and felt great satisfaction that I was able to walk into a job in the marketing division of a city Law firm. It was a large company, with a clear management structure and opportunities for promotion. I believed I was progressing on the right path, at the right time, and that I would naturally start to develop and achieve the success I had been brought up to aspire to.

However, I realised fairly early on in that job that a career in the City was not going to be for me. I was becoming increasingly uninspired, unable to motivate myself to find purpose in the work I was doing and was struggling to conform to the desired mould for my role. This made me anxious, as I had been educated to work hard and to be ambitious and to realise my potential. When I looked over at my boss late one evening, working hard in a position I had no desire to reach, the penny dropped and I resigned!

To be warned by a friend that "you just won't use your brain at all", when I announced I would be leaving, was daunting - especially as it was echoed by others in my social circle at the time. I thought I would be disappointing people which was a very tough emotion to overcome.

Of course there were moments when I questioned my decision, and the sacrifices I had to make to do it, but I have never regretted taking that step into the unknown. I know I am now in the rare position of working in a job that I love and where I can gain so much from what I give. I think everybody is very surprised at how well I have done and, I hope, are proud of me and the job I now do.

To find out what I became watch Becoming Me.

Sarah Kirkness features in 'Becoming Me', a new documentary from Sundog pictures and Randstad UK.