He told the that although he grew up in a single-parent family on a housing estate in Lewisham, his disabled mum always encouraged her children to be positive, and gave them hope.
He said he had a “whale of a time” growing up despite having little money, living in a local community which “looked after each other”.
His said his mum taught him and his two brothers to “raise our expectations”, “never to be victims” and not dwell on misfortunes.
He twice became homeless as a teenager, but said he and his family always saw these as temporary challenges to be overcome.
He managed to get a place at Crystal Palace Academy, but it didn’t work out.
He points to that failure as a key moment in his eventual success, because it made him more determined.
“Thanks to that disappointment and rejection, it put me on this path which is beyond my wildest dreams,” he said.
He had been borrowing money to “keep up appearances” with friends like then-footballer Rio Ferdinand who were being “paid well”, but he was eventually left with an £88,000 debt pile.
To start to clear that, he got a job in a Motorola call centre, and he quickly worked his way up.
He moved to a software firm called Primavera which he helped build up, and made his first millions after it was sold to Oracle: he had taken an equity stake.
Forbes moved from there and was chief executive of two software firms, KDS and CoreHR, each time taking equity stakes, and making millions more.
He also has an equity stake in Forterro, which he said was a firm which makes more than €300m (£250m) in revenue per year and earnings of €130m.
Despite his wealth, he said he never wanted “to lose the value of a pound”.
He was able to buy his mum a home, and his children “have never had to deal with anything I had to deal with” in terms of poverty.
He now describes celebrities like Ferdinand and actor Idris Elba as close friends.
But he told the his roots remained very important to him and he wanted to inspire and give opportunities to others who have not started out with advantages in life.
