Ironically it is that "chequered past" Mr Kennedy is now making a career out of.

The former teenage drug addict and Sydney gang member turned his life around in his early twenties.

A few years later he released an autobiography 'Stabbed Ego: A Thug's Journey to Enlightenment' when he was invited to speak at a local high school.

He is now such a sought after speaker that he is booked out for the rest of the year.

Mr Kennedy was the guest speaker at St Joseph's Regional College Upbeat Festival on Friday, August 30.

He certainly has all the "cool stories" to keep young people engaged.

He grew up in Sydney and despite coming from a "good family" became addicted to drugs and alcohol in his teenage years.

"I was addicted to party drugs, cocaine, speed, pills, acid and base," he said.

"Luckily for me there was no ice."

From the ages of 15-22 he was involved in street gangs almost dying himself.

"I was leading this heavy existence, where I was this leader of this gang, it created a false identity where I felt that I had to live up to that person," he said.

Mr Kennedy traces his troubles back to being labelled early by a friend as "dumb".

"It affected my confidence, something as simple as that, I started believing that and it just spiralled out of control," he said.

He believes "false identity" is the cause of a lot of mental health problems among young people.

"This separation of who we are deep down and who we are meant to be and who we feel we ought to be," Mr Kennedy explained.

High school brought with it a new set of problems for Mr Kennedy.

He was immediately bullied because of his weight.

"I ended up getting into a fight with one of the older kids, both my father and my older brother were pro boxers and I ended up beating the kid in front of the whole school," he said.

"From that day people knew me as that fighter and again I was living up to that false image."

By year 10 he was expelled from school for fighting and fell into gang life.

Mr Kennedy said there was no specific catalyst in getting his life back on track.

But a number of seeds were planted along the way.

These included seeing a couple of friends die, his father giving up alcohol and the realisation that "all his life he cared what other people thought".

He also discovered a passion for boxing.

"I found a passion, which is boxing and I ended up losing all this weight," he said.

As for the drug addiction that gradually eased as he got his life on track.

"I had a very overactive mind," he said.

"The only way to silence those frantic thoughts and forget about my past and not worry about my future was the drugs and alcohol."

Mr Kennedy urges young people to go on a journey of self-discovery, breaking away from what other people think and social media.

"I talk about how when we come into the world we are this pure, unstoppable being with unlimited potential, we our in our pure state, our true selves," he said.

"As we get older we get labelled with a certain thing, we might get a negative belief about ourselves, someone might call us something and it creates a false identity."