During his time in Nigeria, the future boxing superstar lived a strict school life and learned the value of discipline through early morning wake ups.
Speaking to supermodel Jourdan Dunn for Vogue, Joshua, 31, said: “I spent about nine months in a boarding school, six months in a boarding school.
“Really, tough. No nonsense, education is, ‘I want you to be a doctor or a lawyer’. There’s no YouTube, no boxing.
“None of that, it’s either doctor or lawyer, simple. So education is important in Nigerian schools and especially in a boarding school.
“Five in the morning, that’s when I’m getting my deep sleep as well normally in London!
“Waking me up at five in the morning, and if you don’t wake up, they bust through the door, ‘Wake up!’
“Discipline, so tomorrow through your mistake, you’re not going to make the same mistake again, so that’s why I believe mistakes are good.”
To spark fear into his rivals on the streets, Joshua turned to the gym – with no intentions of a boxing career at first.
He revealed: “So I was on tag for like 14 months, went remand, was in jail for a little bit, come back and that’s when my cousin – when I was still on tag when I came back as part of a bail condition – started training.
“Because I wanted to get strong for when I make a return to Watford I don’t want to be the same skinny… so boxing wasn’t even a primary thing.
“So when I moved from Watford into London, I started chilling with my cousin in London, so he was boxing at the time.
“I was driving, I had the whip, so I’d take him to the gym and I used to sit back watching these lot box thinking, ‘I’d smack up these guys, I could do this’.”
After learning the basics from his cousin Ben Ileyemi, Joshua also found inspiration from Tyson’s story.
Iron Mike by the age of 13 had been arrested 38 times before he was adopted by his former trainer and mentor Cus D’Amato.
After channeling his anger in the ring, the American in 1986 went on to become the youngest heavyweight champ of all time, aged only 20.
Having seen Tyson go from criminal to coronation, AJ was convinced he could do the same.
Joshua said: “I watched Mike Tyson, who I saw this kid he was about 13, he was getting into a whole heap of trouble, juvenile detention centres and I think that’s when he got into boxing at 13.
“But from such a bad background where you’re deemed the worst in society to becoming one of the most praised champions that the world has ever seen all through hard work and discipline, I felt like I could do the same thing.
“So you can only achieve what you see and what you believe and I just felt like I could do it.”
Joshua’s dream turned into reality as in 2012 he won gold at the London Olympics for Great Britain, only five years after he first started boxing.
And like Tyson, he reached the heavyweight summit with unified titles.
AJ is set to return to the ring in September against mandatory challenger Oleksandr Usyk, 34, having missed out on facing Tyson Fury, 32.