Nineteen years at Bridge of Don Academy; 15 as principal teacher. Lifers who were jailed when I started had been released on licence; children had begun appearing in my classes chorusing “My ma kens you.” I was seriously stir-crazy. It was time to move on.

The brotherhood of assistant headteacher had once fleetingly mesmerised me, but I withdrew from a leet after the customary visit, concluding that this was no job for a grown man. Running the modern studies corner shop was infinitely preferable to becoming a faceless corporate suit.

So, where to? Bridge of Don was a pleasant enough school. The pupils were largely agreeable and my department had passed muster with Her Majesty’s inspectors. Relative ratings had been through the roof for years. But it had become too predictable, too formulaic. There is no escape from the truth: I was institutionalised.

An advertisement in The TES Scotland beckoned: “Principal teacher of modern studies, Albyn School for Girls”. I applied and within three weeks I was appointed. I had made an irrevocable decision. What was I thinking?

Interestingly, none of my friends and colleagues queried the move. National trainer George Clark simply shook his head and murmured: “Teacher heaven, Graeme, teacher heaven.” A former physical education colleague began his letter: “I have never been jealous of anyone before I” I entered the world of the Stepford pupil. I imagined that I was the subject of some wind-up when, on my first day, I uttered the word “homework” and immediately the slap of notebooks could be heard hitting every desk. Pupils came up and told me how much they had enjoyed my lessons. Some asked if I was enjoying my new job. Others simply signed up for the subject in droves, “because we heard you were a good teacher, Mr Pont, and your lessons are fun”.

I had the vague twilight zone feeling that all was not as it seemed, but as the months sped by I realised that this was a parallel universe which had existed for years in Aberdeen, unbeknown to the average teacher.

This was a school where the most adventurous group-work based lesson, which would lead to grievous bodily harm or a blood bath elsewhere, was picked up and acted upon with a spirit of co-operation, tact and diplomacy. Had I discovered the fabled hidden lair where wacko 1970s college lecturers and academics had tried out their “new” methodologies and generalised, in arrogant wisdom, that theirs was the way forward for all children? Those of us who have taught in bog standard comprehensives are only now recovering from the resulting post-traumatic stress disorder.

It was both stimulating and challenging to enter such a different environment which had evolved over many years. The ferocious work ethos, the commitment to charities, the breezy confidence and lack of pretensions were the recognisable hallmark borne by all. The sum of the whole was greater than its individual parts and over time, even the would-be recalcitrants felt compelled by an invisible, yet potent force, to modify.

It was easy to understand why parents, many at considerable personal sacrifice, were willing to part with around pound;5,000 a year to offer their daughters an education which treated each as an individual within a clear and compassionate ethos.

Albyn is a place largely free from the paralysing form filling which typically preoccupies principal teachers; a place in which professionalism is expected and valued. Being a small school, each teacher is involved in decision making and is aware of the commercial realities of life. If the school, and the individual teacher, was not to meet the needs of parents, then the consequences could be uncompromising. The governors, who are mostly parents and encompass a range of local legal, business and academic expertise, are responsible for the development of the school, its finances and priorities. They were quick to act in 1999 when the then head was accused of sexually harassing a non-teaching, male member of staff.

Like all independent schools, Albyn operates in a competitive market and - as is the way with all competition - the customer is valued highly and listened to. This is a perspective that some cynical staffroom good ol’ boys, living a life of Brezhnevian institutional security courtesy of the public pocket, might find enlightening.

It is now over two years since I changed jobs. Last term I took up another principal teacher post, in a large local authority school. The opportunities and possibilities are greater and I have two members in my new department to work with, which offers fresh challenges and a broader view than I could have on my own.

So, what have the past two years taught me? A lot, both personally and professionally. I examined my life in the face of a pernicious advancing monotony and challenged conventional wisdom on a range of issues. I had been living in a womb-like comfort zone for too long which had become devoid of risk or unexpected challenges. I realised I could change things.

It was flattering to realise that two very different employers had chosen me to lead their modern studies departments. I was compelled to evaluate what I had been doing professionally and was surprised to realise the achievements and successes I had hitherto never felt it necessary to reflect upon.

I also realised that a cosy staffroom filled with friends was not in itself a sound enough reason to remain in professional stasis. It was revealing and reassuring to fit in so quickly to my job in the independent sector, where my new colleagues reflected the composition of any staffroom. I was motivated to make an effort and establish myself in a new environment rather than repeat well-rehearsed behaviour patterns. I found that I was using aspects of my personality which had snuggled into deep hibernation years ago. Life was suddenly more interesting.

Teaching unfamiliar youngsters was liberating. I had the freedom to explore and not be restricted by habit or expectations, thus allowing me to develop the curriculum in new, more interesting ways. Being on my own allowed me to do this with unheard of speed.

Small classes allowed me to get to know the needs and abilities of individuals quickly and to act accordingly. A universally accepted work ethic, fuelled by high aspirations on the part of pupils and parents, reinforced the importance of the school and home partnership. High expectations extended to all aspects of school life. Shy, hesitant girls gained confidence in an environment which rewarded participation and mutual support. Facilitating this was a strong house system, prefects who had a sense of purpose and duty and a pervading atmosphere of tolerance. These are lessons I take with me.

All-girl classes do work. The researchers are right. Participation is not inhibited by ribald or sarcastic male put-downs, nor is there an atmosphere where academic success attracts the sobriquets of “swat”, “boff” or worse. Girls on their own are co-operative, relaxed and supportive in ways which I have not seen in mixed gender classes. The weaker are supported more and having a go, no matter what the outcome, is seen as normal. In addition, an uncompromising school uniform policy obviates the need to compete in the fashion stakes and the associated bitchiness which inevitably accompanies such preoccupations.

I also came to realise that it was not the social background of the pupils which was responsible for their harmony and commitment, rather it was the unambiguous school values which were continuously reinforced in various ways in the single gender environment.

I now realise that there is life after 40 and you don’t have to climb the greasy pole of promotion, with its attendant administration and alienation from the classroom, to get a new life. Making the moves I have has opened my eyes, not to mention my mind.

Many principal teachers eschew further promotion and may begin to feel they are stuck where they are indefinitely. Local authorities could help by making it easier to move between schools, which would facilitate more personal and professional development and a cross-fertilisation of ideas and practices. Students would benefit, teachers would benefit and ultimately the entire education service would too.

Are we not too wedded to the idea of teachers serving a lifetime in a particular school? Perhaps contracts should not specify a school at all, with the expectation that after a period of, say, five years a principal teacher would move within the authority to a different school for another specified period of time and so on.

Change is scary but, as one who made the break, all I can say is do consider the option of a sideways move if you are feeling frustrated. You probably have a lot more to offer than you think.

Graeme Pont is principal teacher of modern studies at Cults Academy, Aberdeen, and author of Living in a Democracy (Pulse Publications)