School days are said to be the happiest days of your life, but for many people nothing could be further from the truth.
As pupils across Northern Ireland get ready to settle into their classrooms as the new school year begins, a potential threat hangs over the heads of many schoolchildren - bullying.
Eamonn Devlin confronts painful memories in the programme
It's the subject matter of the powerful new documentary, Bully For You (BBC One NI, Monday 1 September at 9pm) and a subject very close to the heart of the programme's producer and director, Eamonn Devlin.
In Bully For You, Eamonn turns the camera on himself as he goes on a deeply personal journey to reveal the long-lasting, emotional scars of being bullied as a child.
The programme, which was a year in the making, is a hard-hitting and at times harrowing account of Eamonn's own 25-year struggle to come to terms with the torture he experienced as a 13-year-old schoolboy.
More used to looking outwardly as a filmmaker, Eamonn forces himself to look inwardly and face the disturbing memories of being bullied at school which have haunted him ever since.
He must make one of the toughest decisions he has ever had to make; whether he should come face to face with his childhood tormentor.
Eamonn said: "I remember that it was like the whole world hated me, I felt utterly alone. I was only 13 and didn't have the where-with-all to cope.
"Everyone just stood by and watched; many even joined in. You're either with the bullies, I suppose, or against them. They were afraid that if they stepped in the bullies would start on them.
"So it was a very claustrophobic world - a world in which I seemed to be the only inhabitant. And that was very sad for me. In many ways, it still is.
"So when I began my search to meet the bully and hopefully lay to rest the terrors of my past, it brought back many of the negative emotions that I had felt as a young boy.
"What was he going to call me, how would he treat me, would he sneer and mock me one more time? How would I react... I'm bigger and stronger now? Would he even remember me?
"This road that I was leading myself down had many potentially negative pitfalls. What was I going to do?
"It's strange looking back. Over the past 25 years I've learnt to cope and have been able to draw on life's experiences, but it has not been easy.
"Making this film has not always offered the answers to my questions or the solutions to my problems."
On his journey, Eamonn meets three individuals who were also bullied at school.
They share the mental and physical anguish each experienced at the hands of their bullies and reveal how it has led them to either self-harm, use drugs, over-eat or even contemplate suicide.
He also hears from families of victims of bullying, including the sister of a young girl who took her own life at the age of 14 through bullying.
Andrew, now in his 30s, recalls his memories of being bullied in school and when describing one particular incident said: "It's so real, as I say, I can close my eyes and I can just see it all happening and I can see it all unfolding.
"I've spent nearly 13 years now going through it all in my head and thinking what could I have done differently to change it."
Eamonn said: "When you meet people who have similar experiences to you it makes you feel very humble that they can sit down and share their intimate and hurtful stories with you.
"I really admire their courage and hope that the film lives up to their expectations - that it will help and focus people's minds, whether victim or perpetrator, whether family or friend, that bullying isn't just harmless fun.
"Bullying leaves its scar - a scar that can appear in the most unexpected circumstances, at the most inappropriate time; a scar that you never want anyone to see."
Exploring his own personal experiences of being bullied, Eamonn meets one of Ireland's leading authorities on the subject, Professor Mona O'Moore, from Trinity College, Dublin, and trained counsellor Jim Deeds, to discuss his torment and talks to his own mother and an old school friend to go back over those painful days.
Professor O'Moore talks to Eamonn about the sense of dread he experienced every day in school at the hands of his bully,
He said: "I think when it comes to somebody being victimised you are obviously a very good example because we know from research and from anecdotal evidence how children's concentration goes because all one's cognitive resources are simply going towards how to keep safe.
"You probably experienced great tension. You probably experienced disturbed sleep. The worry of what's happening to them once the bell rings and they are out in the corridor or out in the playground or whatever."
And talking to Eamonn about his feelings that some people may think he was too sensitive or should have adopted an attitude of 'what doesn't kill you makes you stronger', Professor O'Moore said: "It is so important to dispel the myth that bullying is a normal part of growing up and that it's character building; it is nothing of the sort.
"We know that quite apart from the physical injuries, it's the psychological injuries and the name-calling, and we know now that this can essentially change somebody's identity and words can break your heart.
"So what is normal about that? What is character forming about that?"
Eamonn said: "There was a lot of pain in making this journey and even afterwards I still ask myself was it all worthwhile, what have I really achieved?
"It's only now, almost two years later, that it has begun to make sense; that I have started to feel a form of closure.
"I must say though, I am very nervous about the film being broadcast. I feel that it will show a side of me that I have bottled up for years, kept hidden.
"Now it's out there for all to see. I hope the film goes in some way to highlight the pain and suffering that bullying causes and if even one person has second thoughts about making someone else feel bad about who they are, then it will have achieved its goal."
Bully For You is an insightful, moving documentary which illustrates how, for many, schooldays are not the happiest of their lives, but instead the most horrific.
A Triplevision production for BBC Northern Ireland, Bully For You is part of the new autumn schedule of powerful local programmes for Mondays at 9pm for BBC1 NI.