Mr John Farren recalls being laughed at by fellow passengers on a Dublin bus; having barmen ignore him when trying to order a drink; and being afraid to bring his children out for fear they would be embarrassed by him.
And all because he had a stammer. Now he describes how his life changed after taking part in a pioneering course run by speech and language therapists from the North Western Health Board.
An eight-day residential course, it is the only one of its kind available in the State.
In some health board areas there is no help available at all for adults who stammer.
There is also a shortage of speech and language therapists working in the health services and few people have gained experience in this specific and "very complex" area, according to Ms Maria McDonnell, who runs the course along with Mr Patrick Kelly.
Stammering affects 1 per cent of the population. It affects people of high intelligence and those with learning disabilities. Men are four times more likely to stammer than women, but no single cause has been found, although a predisposition to stammer may be inherited.
Ms McDonnell said the course focused on psychological aspects as well as speech techniques because people had been "scarred" by their experiences.
"Most people have suffered terribly. They were teased at school, bullied in the workplace and ridiculed in public places," she said.
Mr Farren, who is a shopmanager and part-time taxidriver, said trying to ask for something in a busy shop or pub was always difficult. At times barmen just walked away. "Then they will ignore you for as long as possible. You feel extremely low. It's amazing what goes on down here," he said, pointing to his stomach.
"There is the fear of speaking, the feeling of being inadequate, of being different from everybody else. And you feel worthless. And then there is anger because of it all," he said.
For most people with a stammering problem, Ms McDonnell said, it is "a huge monster controlling their lives" and they go to enormous lengths to avoid embarrassing situations such as speaking in public, or saying certain words.
Mr Farren as a taxi-driver never charged a fare of £3 because he had difficulty saying "three". Another man who attended the course left the scene of an accident, despite the fact he was injured, simply to avoid having to talk to emergency personnel.
The course is run through group work rather than individual therapy, and this is important to its success. Mr Farren said that to share experiences with other people with the same problem made a huge difference.
At times, he said, it was "extremely emotional", but as the week went on they even started to joke about the problem. Practical exercises during the course include video recording the person as they speak, role play of situations that usually cause problems, and telephone work.
Ms McDonnell said there were two different types of stammering, overt and covert. In a covert case it may not be obvious 80 to 90 per cent of the time, but if anything these people usually needed help even more than those with an overt stammer.
"These people are often living in fear of being discovered, and for them it is highly sensitive.
"When they come to us, they are often at breaking point," she said.
She stressed that children who showed signs of stammering must be sensitively treated. The reactions of parents, family or teachers could maintain or even exacerbate the stammer.
A parent with a stammer may often be even more anxious and react inappropriately.
It usually begins between the ages of two and five, and while a small proportion of children will recover spontaneously, it is recommended that a child be brought immediately to a speech and language therapist. It can usually be cured in childhood, and the earlier the child is treated the better.
Mr Farren urges anybody with a stammer to seek help. He has no obvious problem now, although he makes a point of telling people he has a stammer.
"If you are looking for freedom and a new life, do the course, because without question I got out of it a complete change of life."
He always wanted to get involved in his local community in Glenties, Co Donegal, but was unable to. Recently he was asked to chair a public meeting. "I did it without hesitation and I managed very well, but I said at the start that I had a stammer. But for me that is a massive change."
The next course, which is oversubscribed, takes place in Enniscrone, Co Sligo, although further courses will be held. Priority is given to people from the North Western Health Board area, but people from other areas are also accepted.