Shane Mullins had been suspended from school 13 times before he was finally expelled when he was 14.
"I was bould-out," he says. "I didn't like school and school didn't like me."
The building boom was in full swing and work was plentiful. He took up block-laying and by the time he was 15, he was earning a man's wage.
"There was only one thing I was going to spend my money on," Shane says. "Drink. I worked hard all week and partied hard all weekend."
He was 17 when he got the car. It meant independence. He could drive to work and on the weekends, he could take off to wherever he liked.
On the night of October 16, 2005, Shane went to a house party near where he lived in Monivea, Co Galway.
He began drinking. Later, someone suggested heading up to the pub for last orders. His friends knew he didn't have any qualms about getting into the car with drink on him, so they managed to hide his keys.
But Shane found them, and he took off, swerving, to the local pub in Abbeyknockmoy, less than two miles away.
There, he continued drinking. At closing time, he got back into the car and headed back towards the party.
"At that stage, I was well hammered," he says. "I was driving hunched around the steering wheel, my head up against the windscreen."
About a mile from the pub, he lost control of the car. It hit the ditch and rolled into a field. Shane hadn't been driving that fast but, in a stroke of bad luck, the windscreen hit a pillar that had been lying in the field. The pillar came in through the glass and struck Shane's head.
In hospital that night, Shane's friends and family were told to prepare for the worst. His parents, Rose and John, were asked if they would be willing to donate his organs.
But as Shane's friends gathered to say goodbye to him, he began to fight out of the coma.
It was two days before he showed any sign of life, but in the weeks that followed, Shane's body slowly began to come back online. It was an agonising process. He was all but blind and completely paralysed down his right side.
As the doctors worked to save his sight, Shane's large extended family was mobilised and a 24-hour rota put in place, designed to restore feeling and movement into his arms and legs.
It was a painstaking process, which went on for the three months that Shane spent at University Hospital Galway.
"I couldn't eat for the whole three months. I had to be peg fed, through a tube. Cooking smells used to drive me crazy."
At the end of that time, he was offered a place at the National Rehabilitation Hospital (NRH) in Dun Laoghaire. Here, a large team comprising occupational therapists, psychologists, doctors and physiotherapists worked to help Shane's recovery.
"It was when I came out three months later that my problems really started," he says. "My mother had to do everything for me. I used to be my own man, earning my own money. Now I was helpless. I hated it with a passion."
Shane could now walk unaided but his balance was poor and he needed help with the most basic tasks.
Nevertheless, he insisted on going to the pub in the evenings, but alcohol and brain injury do not mix. He would become incoherent after one pint.
He was frequently aggressive, and inevitably, his father would get a call from the pub and he would have to come and literally carry Shane home.
Eventually, Shane was treated for depression in Ballinasloe. It was at this point that he began to turn his life around.
"I used to think I was a hard man. Why would I want to talk about my feelings? Feelings? Would you go way out of that. But in Ballinasloe, I finally realised I needed help.
"That's the thing, you have to realise you need help, that's the first step. I realised that I needed help and I accepted the counselling."
When he came out, Shane was accepted into the training unit back at the NRH, which offers semi-independent living and support services for people trying to rebuild their lives after brain injury. There, he managed to get off drink and when he returned home to Monivea, he was determined, with his family's support, to build a life and regain some kind of independence.
He enrolled in classes at Galway Technical Institute, and there, one of his teachers suggested he talk to the class about his experiences.
He held his classmates spellbound as he talked them through everything that had happened since October 2005.
Their reaction made him think about how he might take what he had learned and turn it into something useful.
In the months that followed, Shane developed a self-help system, designed to help young people face and fight their demons. He calls it D'MESS. Each letter stands for a pillar of his programme – Determination, Motivation, Emotional, Support and Social life. He maintains a website dedicated to the system at dmess.org.
"It's about D'MESS you got yourselves into and D'MESS you can get yourselves out of," he says.
Over the past 18 months, Shane has been travelling around the country, talking to groups of young people about his experiences and his system.
Shane's informal delivery, plus the fact that he's not much older than the people he's talking to brings a power and a credibility to his testimony.
He still wobbles when he walks, is blind in one eye and suffers many of the cognitive impairments that go with brain injury, but he is slowly establishing an independent life for himself, all based around his system.
"I knew I could do it, I just knew I could," he says. "I took on brain injury, and I won."