American comedian Chris Rock does a bit about how you know you really hate your job when you will happily spend time locked in the toilet as a ploy to waste a few minutes, rather than doing the work that you are being paid to do.
We all have hours, days and occasionally weeks where the job seems like too much hard work for too little return.
It was my last session of the day and there had been a behavioural incident. Nothing remotely traumatic, but I was irritated and it left me exhausted.
I returned to the staffroom and slapped my files down on the desk. "Good class, was it?" asked my cheery office neighbour. "Well, no one learned anything and we're all a bit cross, so not one of my best," I snapped.
It had been an overwhelmingly busy working week where I'd traipsed all over the country in the name of further education. This day of teaching was supposed to be my port in the storm: instead it was just another tempest.
As I drove home, I dwelled on how happy I would be if I were to jack it all in and have a life like the mothers of some of my son's friends. They don't go out to work, they attend school concerts in the afternoon and casually call their children's teachers by their first names (I can barely remember their surnames).
I thought back to when my son was little and I stayed at home for a few years. I adored being with my boy but I didn't exactly take to life as a stay-at-home mum like a duck to water - more like a plugged-in hairdryer to water. All things considered, a return to housewifery was probably not a sensible option.
Education is my second career, the first being in the entertainment industry. Maybe I should go back to that. I believe the world of showbiz is crying out for knackered, middle-aged, big women. As an actor, I was lucky in that I worked about 75 per cent of the time, but like most in that profession, I had to take on a variety of other jobs when the roles were scarce and the money was tight.
I have taught fitness classes to pensioners in church halls and worked on cosmetics counters in posh shops, in the kitchen of the world's shabbiest golf club and - in the most character-building experience of all of my temporary employment - as a call centre operative. During that job I spent about a quarter of my time loitering in a toilet cubicle.
Still, it worried me that I was questioning my career, particularly as I bang on about how great FE is all the time. We get to work with all sorts of interesting, challenging, exciting people and sometimes we help them to get their lives back on track. Was this a genuine concern or just the mark of someone in need of a holiday?
As I turned on to my road, I realised I was desperate for a wee. I had meant to visit the ladies' at several times during the day but there was always something more pressing. This urge was my epiphany. If avoiding work by sitting on the loo is the mark of a hated job, neglecting to go at all must mean that I love mine. Problem solved. It seems my pelvic floor is as strong as my career choice.
Sarah Simons works in FE colleges in the East Midlands