I haven’t had to eat humble pie for some time. But each time I have, it has tasted different. This time it was spiced with enlightenment.

During my 30 years in education, I have often employed and worked with supply staff. Sometimes I have been critical of them - made the sweeping generalisation that people working on supply are failed teachers. This term, changes in my circumstances forced me to join them. I lasted a week.

The simple act of going into a school as a “supply” was more demoralising than I expected. The general sense of not belonging; being described by one student as “having a lower status than a non-teaching assistant”; and another finishing a question to me with the epithet “you dickhead”. (Apparently, he liked me. Those not in his favour were described in far more degrading ways.) Alongside this lack of worth as a human being came a feeling that I was not achieving much in class. The national curriculum helps - inasmuch as everyone knows the topics and skills to be learned in a particular subject and in a particular year. But schools have their own idiosyncrasies. They also have varying standards.

Although the days of staff taking boys out into a corridor and caning them because they had no tie are dead and gone, other aspects of school life - acceptable noise levels, and rules on clothing and moving from one area to another - vary considerably.

The variations in behaviour are to be expected. But the differing way schools respond is surprising - this particular school’s dismissal of my anger at being called a dickhead, for example. And there, somewhere in the middle, is the person who doesn’t belong.

My decision to opt out after a relatively short time left me feeling guilty. Guilt that I had failed and at leaving a dedicated team in the lurch. I discussed it with the head. She thought I was being overly critical of my performance but accepted my decision. However, my failure made me think about the reasons why supply staff “fail”.

Supply teachers arrive at a school at times of crisis. Staff absenteeism has reached the point where the curriculum cannot be covered by those remaining. Or, in truly desperate circumstances, there are too few adult bodies to spread between the groups of kids.

From my own experience, the recruitment of a supply teacher often takes place around 8am and the person willing to arrive does so as the school is moving to its first lesson. There is seldom time to do any more than take the person to a room, sow him or her a class of kids and where work is found, and alert the teacher in the next room that “the supply has arrived”.

In the aftermath of September’s petrol blockades, there has been much talk of what people should learn from the experience - what can be done to make sure it doesn’t happen again? I wonder how many schools go through such a process when a supply teacher fails to make the grade or, as in my case, opts out?

For many, the response will be (as mine always was) a shrug of the shoulders and the corporate moan that “you can’t get the staff”. While that may be true in some circumstances, schools might consider other actions to overcome the problem of the emergency supply teacher. Some of these actions may also be valuable for supply teachers recruited in advance - for example, to cover absence at a course.

* Schools usually have a staff handbook with details of routines and procedures. Why not a potted version for supply staff?

* The start of the day is always traumatic, so are there ways of having “stand-by” staff to cover period one - allowing more time to integrate the supply teacher?

* Give more credence to the skills and abilities of the supply teacher when the person is introduced to the class. Such descriptions as “he or she will look after you this lesson” imply baby-sitting, whereas the person concerned may be an expert.

* Other staff could become more involved in the process of covering a colleague’s absence. It might be beneficial to move other staff in the departmental team - helping the supply teacher to become assimilated and ensuring that classes needing special attention get it.

* Schools could designate someone to act as a “buddy” for the supply teacher. We always had a befriending scheme when new students arrived to make sure they found their way around and learned about the school’s mores during those first few days. Why not help the supply as well?

I accept that some of these suggestions will require schools to take extra action at a time of crisis. I accept that the demand for supply teachers at some schools may not warrant this level of preparation. I accept that many supply staff may not need this level of help. But as someone who managed a small establishment with a high proportion of difficult students, I know how difficult it can be to retain supply teachers. Now I think I know why.

Hindsight is a wonderful way of analysing events. I wish I’d known then what I know now - perhaps we’d have kept a few more supply staff. Me? I start my new job on Monday - pushing trolleys at the local supermarket.

The writer wishes to remain anonymous