"The first was when me and a group of my mates were sitting around talking about what length our hair should be if we were to go to Borstal," he said. "Some of us pointed out it shouldn't be too long because people might think we were a bit soft.

"Then another lad pointed out it shouldn't be too short because then you might look too hard and everyone else would want to fight you all the time. This was all done quite casually and without irony because there was a sense of inevitability about the direction our lives were likely to go in."

Fortunately Carl was different. At 43 he's now a multi-millionaire and lives in a beautiful five-bedroom Victorian house – a far cry from the rather less glamorous life he had living on the Wyther Park estate in Armley during the 1970s.

Yet he grew to realise his life would take a different path – and the seed was planted with the second defining moment.

He said: "I can remember having this big argument with one of my three sisters and during it I stormed off and just shouted back at her, 'Well, I'm going to go off and become incredibly successful.

"And even as I was walking away I just though to myself, 'OK, but what does that mean? Successful? What would I do and how would I do it?'"

He did it by entering advertising and marketing where he could explore the artistic bent he nurtured from high school through to three years spent studying art at night school while maintaining a day job stacking shelves.

Despite being told by teachers he would be a failure, Carl went on to take a two-year diploma in graphic design and a one-year HND in advertising before getting a job with agency Judith Donovan Associates, after his mum spotted it advertised in the Yorkshire Evening Post.

From there he worked his way up the company ranks to the point where he bought his boss out and became chairman in 2005 after more than doubling the company's turnover from £9.6m to £19.4m.

By the time he came to sell JDA last year he was a very rich man – though he refuses to say just how rich.

After getting married to wife Stefanie and getting his fingers in a few more business pies and organisations, he also decided he wanted to help young people, not dissimilar to the 'thieves, glue-sniffers and drinkers' he went to school with.

And it was around this time he was coincidentally approached by the production company behind Channel 4's The Secret Millionaire to become one of the undercover tycoons who discover communities on the skids and help them with a series of big fat cheques.

Bleak

Tomorrow night, viewers can see Carl as he leaves his smart Brighouse home for the depressing surroundings of ex-mining village Easington in County Durham – the bleak backdrop to hit film Billy Elliott.

"It did change my perspective on life," he admits.