The In America director shocked many movie experts when he signed up to direct the urban drama, loosely based on 50 Cent's life.
But Sheridan insisted from the start he was the perfect choice to take charge of the gritty project.
He says, "I grew up in an area of Dublin that was very poor, and there was lots of heroin. I had fights with kids, addicts, and I had to defend myself.
"The Irish experience is very close to the black experience, down to the toxic nature of the way we speak."
As well as hiring Dr Dre as an unofficial adviser, Sheridan allowed his stars to coach him on ghetto language he didn't understand and he even researched the history of slavery "to understand where some of the attitudes come from".