It's sod's law. You spend years grumbling about your school, then just as you're about to leave all you can think about is how much you are going to miss the place. All the things that used to drive you crazy suddenly become objects of deep affection. Even whole-staff emails about wet breaks, pupil data and someone's missing phone take on a heightened emotional significance.
I should have known it would be like this. Years ago, after splitting up with my first long-term boyfriend, all the things that made me want to leave him turned out to be the things I missed the most.
Once we were separated, his easy-going nature, his lack of ambition and the fact that he snored during subtitled movies all metamorphosed into virtues rather than vices - a sea change no doubt prompted by boyfriend number two, whose vaulting ambition made Lady Macbeth seem like a dithering social worker and whose cinematic pretensions included watching Un Chien Andalou.
In the words of Joni Mitchell (a firm favourite of boyfriend number one and another reason he had to go), you don't know what you've got till it's gone. I didn't then, and sadly I still don't. Otherwise I'd have been able to anticipate the emotional roller coaster ahead of me.
As an English teacher, my knowledge of Thomas Hardy's grief over the death of his estranged wife should have prepared me for the debilitating sense of loss I feel. When Emma passed away, the randy old codger (who took up with a woman 39 years his junior) felt so bereft that he penned the most haunting elegies ever written; it being one of life's little ironies that you are never more attractive than when you are dead.
If I had a better ear for rhyme, this would be a tear-jerking sonnet about marginal gains, target grades and three sub-levels of progress. But as I can alliterate, it's my fear of the future that's fertilising this fondness for the past.
Although I am moving to a fantastic school, in the short term I will have to struggle on without the crutches of reputation, insider knowledge and the support of old friends. And it scares me a bit. In the familiar corridors of my current school, I know what to expect, when to expect it and where to shelter in a storm.
I know, for example, that if my projector conks out in the middle of Of Mice and Men I can dial 254 and a mild-mannered man called Trevor will pop along and fix it. I know that the stationery cupboard will always be full of exercise books and Post-its thanks to my colleague's magic catalogue. And I know that if my students get too rowdy, the merest whisper of the deputy headteacher's name (Tywin Lannister meets Lord Sugar meets Mr Drew) will be enough to keep them in check.
It will be a while before I can rely on such knowledge in my new place of employment. Until then, I will just have to press Ctrl and F8, hope the picture comes back and wait for the occasional life-affirming email about black trainers lost in the playground. I could, of course, ask for advice from my new head of department. If only she wasn't me, I'm sure she'd be very helpful.
Beverley Briggs is a secondary school teacher from County Durham