Los Angeles - Jay Z learnt his business skills from dealing drugs.
The hip-hop mogul found it easy to set up his Roc Nation record label and build a musical empire because he already had years of experience illegally selling crack on the streets of Brooklyn in New York City.
He told Vanity Fair magazine: "I know about budgets. I was a drug dealer. To be in a drug deal, you need to know what you can spend, what you need to re-up."
The 43-year-old reformed family man - who has 20-month-old daughter Blue Ivy with his wife Beyoncé - wishes he had got out of the drug scene earlier and thought about the big picture instead of focusing on the instant cash.
Jay Z added: "Not until later [did I have regrets], when I realised the effects on the community. I started looking at the community on the whole, but in the beginning, no.
"I was thinking about surviving. I was thinking about improving my situation. I was thinking about buying clothes."
The music mogul is reported to have raked in $42m in the past year, adding to a net worth of about $475m, a far cry from his original "exit strateg" of setting up a barbershop.
Jay added: "If you want to start some sort of barbershop or carwash - those were the businesses back then. Things you can get in easily to get out of [that] life.
"You have to have an exit strategy, because your window [for dealing drugs] is very small. You're going to get locked up or you're going to die."