The great Michael Marland's book Craft of the Classroom was the only book I read on my PGCE in the 1980s. I don't know why one needed to spend a whole year learning how to teach when one could just read his book.
I have been reminded of the book as the summer holidays approach because one of its wisest bits of advice was that teachers should go into school on the first day of the holidays, finish any outstanding admin, take down displays, put up next year's, and then forget about school until the start of September.
I don't follow this advice myself. That's my fault.
The summer holidays are clearly vital in restoring your equilibrium. It is the teacher's annual equivalent of a good night's sleep after you have been up at an all-night party, or having a sleepless night worrying about a difficult Year 10 class. If it goes well, it is a massively rejuvenating experience.
But how exactly should one spend the summer? I'm always intrigued about what colleagues have been up to in their holidays. After 25 years in common rooms, I have reached several conclusions. Here are four of them.
Do something energetic. Nothing is so relaxing as getting physically exhausted. Sitting around on the beach is great, but if the main exercise is going off to find the drinks kiosk or politely declining the swarm of beach vendors offering necklaces from Shangri-La, then you will return to Gatwick or Manchester feeling over-indulged but under satisfied. Beach holidays can be fine, but get up for the early morning aerobic session, or an evening run after the heat dies down. Everyone knows food tastes much better if one has worked up an appetite.
Be bold. Don't go year after year to the same destination in Brittany or on the Algarve. If you had a fabulous holiday somewhere, never, but never, go back to the same place and imagine it will be just as good. You might tell yourself it will be. But it won't. Going back after five years is a different matter.
Try different destinations. Surf the net for cheap deals and fascinating ideas. Rafting in Iceland, horse riding in Morocco or mountain walking in Croatia can turn out to be cheaper than two weeks in Nice. Try something that scares you. Afraid of drowning? Go on a sailing holiday. Scared of heights? Go walking in the Alps. Fed up with commuting? Try going on your holiday by train rather than flying. Afraid of running into your pupils? Go to Salamanca.
Go outside. No one has ever explained to me why sleeping under canvas, eating food cooked outside, and going to peculiar toilets should be fun.
But it is. Why do we love eating outside in restaurants? I have no idea.
But it works. So does camping. For pound;100, you can buy a tent for the family, and you can spend each night in fabulous locations, where no hotel could be placed, either for free or for perhaps pound;20 for all of you.
It has to be worth trying.
Finally, come back to holidaying in the British Isles. The best holiday I ever had was taking the children camping in the Shetlands. I'm not certain they would look at it in quite the same way. If you haven't experienced Cornish fishing villages, the Welsh mountains, the Lake District, or the Scottish Highlands, now is the time.
Personally, we are taking a train to Italy, camping in Normandy and I will be walking on Offa's Dyke. I hope every reader has a wonderful summer.
Dr Anthony Seldon is master of Wellington college