If we're all going to be teaching longer than ever, what kind of teachers are we going to become? Are we all doomed to turn into clapped-out cynics like Grantly Budgen from Waterloo Road?
Not necessarily. The jaded older teacher is a myth. I have met plenty of older teachers in whom the love of teaching still burns bright. Brighter, perhaps, than when they were young. Why?
The longer you teach, the more flexible your mind becomes because you have seen your knowledge through thousands of pairs of young eyes. Jon Snow, the Channel 4 News presenter, was once asked, "Are you as excited doing the news now as you were when you started?" He replied, "I'm more excited now because I can do it better."
Getting better at what you do is one of the great unsung joys of growing older. You're faster, yet you know when to stop in your tracks and savour something before rushing on to the next task. You don't get too upset about things because you know how this kind of silly argument usually ends. You get better at not sweating the small stuff.
Being with young people all day may exhaust the body, but it keeps the mind stretchy and supple. I've had other jobs and none of them ever made me live in the present moment as much as teaching does. Yes, we do a lot of planning. Yet, once that classroom door is shut, we're with young people. The young live in the moment and they take us with them.
We meet them there by knowing them as well as we know our subject. We have to know our stuff, yet constantly see it afresh from each new child's perspective. "Romeo and Juliet can't die! Why do they have to die?" It gets me every time - dealing with their first response to something I have known for decades.
"Teaching keeps you young," they say. After teaching 10X I feel about 100 years old, but after a bubble bath and a glass of red I have revived enough to agree. We have no choice but to engage with how our pupils see things. It's like having mental windscreen-wipers. Pupils often ask questions I have forgotten to ask. "Is this a true story?" plunges me right back into medieval Scotland and why Shakespeare decided to make that Macbeth couple so creepy.
The Russians have a word for this process of being made to see something familiar in a new light: ostranenie or "making strange". The term was coined in 1917 by Viktor Shklovsky, a literary critic who was fascinated by a story Tolstoy had written from the viewpoint of a horse. "It is the horse's point of view that makes the content of the story seem unfamiliar," he wrote.
Yet, young people do not need art to "defamiliarise" things. Everything is new to them already. Teaching keeps us young because, while we are guiding our pupils through our world of knowledge, they are making us see it again for the first time.
There is something else that keeps teachers young, by putting us on the same level of curiosity and wonder as our pupils. This is the simple fact that knowledge is infinite. No one felt this more deeply than Sir Isaac Newton. Looking back on his life, he said he was "like a boy playing on the sea-shore and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me".
Catherine Paver is a writer and part-time English teacher.