Given my background, I might easily have gone into teaching instead of acting. For the first 11 years of my life I lived in a house next to the tiny village primary school in Broughshane, Co Antrim. My father was the inspirational headteacher of that school. So teaching is in my nature and in my nurture.

All three of my elder sisters followed in my dad’s footsteps and for years I felt that teaching should also be my calling. But the truth is that when I looked at my dad, Jim Nesbitt, I knew I could never be as good. He was born to teach in a way that I never felt I was.

What was it that made him the best teacher I ever knew? Put simply: vocation, vocation. He came from a clever working class family; he and his brothers consistently got high exam scores. He could have gone into any profession, but teaching was the job that inspired and defined him; he was never happier than in the classroom.

I experienced this at first hand during what seems like an idyllic childhood. I went to my dad’s school between the ages of four and 11, stumbling across the lawn from our house to the one classroom where all 32 of the school’s pupils were taught.

Aside from us, all the other pupils in that school were children of local farmers. None were wealthy, but by the age of five they were all learning the recorder and by eight they were travelling around Ireland playing Bach preludes on the instrument. In the summer months when it was too hot to work my dad would take the whole school outside for lessons, and in the winter when it rained we’d stay inside and he’d read Charles Dickens to us. He believed in opening every educational window, irrespective of where you were from.

He taught in pre-Ofsted days and wasn’t a “modern” teacher who expected to be his pupils’ mate. He could be strict if need be. You knew who was boss in that class; but he was a good man and a brilliant educator. Ask anyone that he taught, or visit Co Antrim. You’d still find a lot of farmers there who can play a musical instrument or who adore Great Expectations or who’ll hear a bit of Shakespeare and think: “Oh yes, Jim Nesbitt taught me that.” That is his legacy.

Like all good educators, my dad understood that teaching is not just about opening young minds, but keeping your own mind open. Yes, he was a Protestant who played in a marching band. But he never rammed politics down his pupils’ throats and - as a stand against some of the more rabid types who lived alongside us in those Paisley heartlands - he sent my sisters and me to the local convent to learn piano. He was what you’d call an inclusive Protestant.

Later, of course, I met other good teachers. But my dad had set the bar pretty high. After Broughshane I went to secondary school in Coleraine, which seemed huge and impersonal in comparison. I found it frightening, and I dealt with it by being an eejit. I was bright, but more interested in girls and having a laugh with my mates than in studying.

I got into the University of Ulster to study French, with a view eventually to teaching that subject. But the whole time I knew that it was not something that I had a burning desire to do. I jacked it in at the risk of breaking my parents’ hearts.

But, though they may have been privately horrified, it was my dad who suggested drama school. As a child, he’d dragged me to auditions at the local theatre. With a good teacher’s unerring instinct, he always understood what it took me many years to admit to myself: that acting was my thing, just as teaching had been his.

I hope, and believe, that I have done my dad proud, although there is still a part of me that would have loved him to see me teach, if only for a day. Perhaps, in my case, the teaching gene has skipped a generation. Now my nine-year-old daughter, Peggy, worships and adores my middle sister, who still lives and teaches near my parents in Coleraine.

Peggy loves nothing more than to visit her classroom and help out. And maybe we’ll discover that she has the teacher’s calling too. There is part of me that thinks: “Be a teacher, not an actress, for God’s sake.” My dad, I know, would love that.

James Nesbitt, 43, has starred in many dramas, including Cold Feet, Bloody Sunday, Jekyll, Murphy’s Law and The Passion. He is currently in the three-part ITV drama Midnight Man. He was talking to Daphne Lockyer.