Idris Elba wanted to portray Nelson Mandela as a "real" person and show parts of his personality that the public were not aware of.
The British actor was conscious of emphasising the human side of the late anti-apartheid campaigner in new biopic, 'Mandela: Long Walk To Freedom', by showing his sense of humour and his penchant for women - parts of his personality the public may not be aware of.
He told French website AlloCiné: "He's a huge worldwide citizen. Everyone knows what he looks like, what he sounds like. I realised that he has a massive aura. We would always see Mandela on the TV, on the news, but we would never know his aura, it was so big.
"I never met him, but everyone talks about how he walked into a room and you would feel [special] when you met him. He was also very funny and was always making people smile, which is very funny because he seems so serious.
"It's kind of interesting to know that he liked to joke, he's a human. He had his flaws, he had his moments. We wanted to make him real."
The 'Pacific Rim' star refused to watch any other actors' portrayals of the former President of South Africa because he wanted to stay true to his own interpretation of the icon, who passed away aged 95 last December.
He said: "I didn't want to see other actors doing Mandela because it would either intimidate me or deconstruct my vision. I don't look like Mandela, I'm much younger.
"This was our version and I was very selfish about watching anything else, I wanted to focus on what I was doing."