At this time when schools are resuming their work after the summer break, I thought it might be apt to reflect on the profession I followed during my working life: teaching.

You may be familiar with George Bernard Shaw's famous aphorism: "Those who can, do; those who cannot, teach."

A kinder and less cynical view came from Benjamin Franklin. "Teachers affect eternity; they never know where their influence ends."

The teacher envisioned by Franklin rather than the one lampooned by Shaw will relish the opportunity to nourish and inspire young people, and to make this the cornerstone of his or her daily work.

What a challenge! What an opportunity! What a privilege! What a responsibility!

Think back to your own schooldays for a moment. Focus on an occasion when you felt proud, affirmed, happy or relieved.

Focus now on a moment when you felt hurt, aggrieved, frightened or humiliated.

There is a likelihood that in either or both of these scenarios, the memory of a teacher emerged.

I remember noticing a poster on a classroom wall many years ago which read: "They may not always remember what you taught them but they will never forget how you made them feel".

How true and profound that is, and how central a quality ‘kindness’ is for a teacher to have!

When I look back on my own school days, like most people of my vintage, I can recall a range of approaches from a variety of teachers, from the encouraging to the unjust, from the inspiring to the brutal.

Most of them, thankfully, were positive and affirming.

I would like to share with you a brief memory of three teachers who had a profound effect on my education and my chosen career path.

I can only recall one single incident from my year spent in High Infants class in the Convent PS, almost 70 years ago now.

I recall clearly Sr. Clement (later Sr. Helena Hunt) praising me in front of the class for being able to read the word ‘nasturtium’ in a story about red and yellow nasturtiums growing out of an old, discarded boot.

I walked home a foot taller than usual and couldn't wait to tell my parents!

This was at a time when the ruler wasn't always a stranger to the knuckle where the teaching of reading and writing were concerned.

About 15 years ago, I discovered quite by accident that she was living in a retirement home in Lurgan, and I decided to visit her.

She didn't recognise me initially, not least because I had hair where my face used to be, and skin where my hair used to be.

When I told her my name, she immediately said: “Ah, Joe Corrigan! I remember you reading the word ‘nasturtiums’ in my class – you always loved the reading!"

I was incredulous and quite moved. What recall, and what interest, after almost 55 years!

She told me who sat beside me, in front of me and behind me in the classroom, and much more, with almost photographic clarity.

Her gentleness and patience while teaching us to read all those decades ago provided a standard to aspire to all through my own teaching career.

Sadly, she died a few months after our brief reunion, but not before I was able to thank her for her kindness.

If Sister Clement shaped my desire to be a teacher, then Colm Gillespie – an A-Level teacher I had in St. Michael's College – was instrumental in my becoming an English teacher.

I have always thought that a teacher who does not love his or her subject specialism is fighting a losing battle.

Young people are not fools, and can quickly distinguish between enthusiasm and indifference.

Colm Gillespie loved English literature in all its forms, and was highly-effective at transmitting this to his students.

He was challenging and provocative in the best senses of those words.

Thanks to his guttural voice, erudition and unbridled enthusiasm, I grew to love the works of George Eliot, Thomas Grey, Oliver Goldsmith, John Keats and, of course, Shakespeare.

He taught far beyond the prescribed set-list, and would read passages from other authors such as Graham Greene, Eric Ambler, Kingsley Amis and Ernest Hemingway, often lending his own copies of books to his students.

He encouraged us to read quality newspapers such as The Guardian, and The Observer, and treated us as adults.

Sadly, he died far too early, but not before he had developed critical thinking skills and a love of literature in many cohorts of students.

The third teacher I remember with particular affection is Seamus Heaney.

I was lucky enough as part of my English degree at Queen’s University Belfast to be placed in a small tutorial group, and allocated to Mr. Heaney for two years.

He was immediately different. We quickly realised what a wonderful wordsmith he was – the best talker on literature, as well as the best writer I had ever come across.

He used, in Coleridge's famous definition of poetry, "the best words in the best order" to describe the intimate, the familiar, the natural and the real, and of infusing local detail with universal significance.

What a huge privilege it was to be in his company, and to be taught and educated by him.

He was a decent singer, too, and was personable and friendly – I recall him attending one of our student parties and singing a rousing version of, "Come All You Tramps and Hawker Lads".

Among my most prized possessions at home are two of the literary essays I had to write for him, which contain his handwritten annotations.

I'm glad to report I received a B+ for one, and an A- for the other.

Seamus Heaney confirmed in me a desire to teach English literature and poetry in particular.

And so, teachers, as you start back to work this month, I wish you all the very best.

Your job is challenging. You will be a subject teacher, a social worker, a firefighter, a policeman, a barrack-room lawyer, an accountant, a saint and a counsellor, but never underestimate the importance of what you do.

As a teacher, you fill the heads of your students with knowledge and skills, and their hearts with kindness and respect.

You will also be creating memory banks which will last forever.

In shaping and forming young peoples' futures, you are walking on sacred ground.

Good luck, and thank you for the great work you do.