I have spent most of my career teaching 11 to 18-year-olds. Latterly, I headed the English faculty in a comprehensive of some 1,500 students. It was great and I enjoyed most of it, but I decided to downsize and do something different.
Now, in the box marked "occupation" I put "writer". I like doing that. It makes a change. But, I have to confess, I do sneak into the classroom once a week.
I suppose I need my "fix". This time, it's a rural primary school in the depths of the Scottish Highlands. My brief is to teach language, literature and drama to eight to 12-year-olds.
Although, technically, I am still teaching, what I am doing is as far removed from my previous job as bus driving is from bricklaying.
For a start, instead of driving to work through the snarl of traffic, I drive in my very old 4x4 through ridiculously beautiful countryside to a tiny school, where the pupils greet me with big smiles and enquiries about how our polytunnel (a kind of polythene greenhouse) has fared in the gales.
It's lovely, but it's like learning a new job. Fortunately, my headteacher is wonderfully helpful - as is the cook, the secretary and the cleaner, not to mention the children themselves.
My lessons are meticulously prepared (they have to be) and usually they are OK. Sometimes, though, I realise how inept I am. For example, the other day I was holding forth and the class appeared to be impressed until one tiny child started crying very loudly. Horrified, I tried to comfort her, but to no avail until her brother - much older - informed me in his beautiful Highland accent that I was using too many words. Apparently, she doesn't like too many words.
I assured her that I would cut down on the words, and the tears dried instantly.I've been very careful ever since.
It's probably a lesson that every teacher should learn - that too-many-words thing.
But don't let me give you the impression that these children are angelic.
They tried all the usual things on their new teacher. The head was away and had told me to listen to the pupils reading. I called P5 (two children) to read. One claimed that it was not his reading day. A boy at the next table assured him that it was.
"How do you know?" said Boy 1. "You're not even in my class!"
"No," replied Boy 2 with the assurance of one who knows he's in the right.
"But I was last year, and P5 always read on a Wednesday!" Quod erat demonstrandum.
One becomes very aware of the difference a table makes.
And that's another thing that involves a steep learning curve - teaching children of such varying ages and abilities.
I am in awe of teachers who do it day by day. It's like trying to juggle six balls at once. Mine keep crashing to the floor as I realise that P7 are finished while I'm not half-way through my lesson with P4.
I used to think I was pretty good at teaching groups, but this is something different. This is miracle work.
Fortunately, these children are very good at working on their own, and this ability gives them a maturity that was rare even in my Year 11 pupils.
Let's hope they don't lose it at high school.
Then there is lunch time. We all sit round the table together and are served a meal cooked on the premises. Proper food with vegetables and gravy. And all the pupils eat salad - they even fight over the salad bowl.
More miracles. After asking if they can leave the table, they go out to play in green spaces while we have a cup of coffee and prepare for the afternoon's work. Often, we share this time with the under-fives, who are not allowed to go out to play on their own.
I realised in one surreal moment how much my life has changed when I was interrupted during a high-level discussion on medium-term planning by a child whose head did not reach even as high as the table.
"Mrs Baker," she said. "I've brought my frog and my torch today because my frog doesn't like the dark. I've no batteries, though. Do you have any?"