Bogdan Obradovic has seen a lot in a life which has been dominated by tennis and politics.
A promising junior player who moved into coaching aged 18, Obradovic was approached by Djokovic’s father Srdjan to guide his 10-year-old boy.
Later, Obradovic went on to become Serbia’s Davis Cup captain – leading them to one of the nation’s greatest sporting triumphs when the team containing Djokovic won the trophy in 2010. Now 52, he serves as a member of Serbia’s parliament.
“Novak’s father and I had some mutual friends and they told him I was a good coach and could maybe help him,” he says.
“We did one practice and I was completely shocked.
“He was completely prepared. He was warming up, he had a bottle of water, a banana, a towel, everything. I had never seen that from a kid so young.”
Obradovic knew he was a player – at that time “weighing around 25kg” – destined for the top.
During the bombings he says they worked together “every day”, going around Belgrade in search of courts they didn’t have to pay to use.
“By that time people knew Novak and he was already popular so they helped him a lot. We trained at many different clubs,” he says. “It was improvisation but that’s how we did it.
“You know Only Fools and Horses? We love it here. And that is actually our mentality. We do everything through fun. And we always think, like Del Boy, our luck will change.
“We were in a terrible situation during the bombings. You hear the sound and see on the news, people were killed and everything is destroyed. But you can do nothing, and we found a way how to make fun.
“I was with Novak all the time, we practised together and every day was like normal. He was focused but having so much fun at that time. He laughed so much.”
Djokovic often trained at the Partizan Tennis Club, an arm of the multi-sport body which also includes the 27-time national champion football team, plus successful basketball, water polo and volleyball sides.
Dusan Grujic has been the Partizan president for 22 years and says this is the club Djokovic “has in his heart”.
“When you spend 11 years somewhere, like he did here, I don’t know how we could say anything different,” he adds.
“Novak made his first steps at Kopaonik, but that was only for a short time. When he was six, he came to Partizan. We provided him with everything we could and everything he wanted.”
Photos of their greatest son, along with other alumni including 2008 French Open champion Ana Ivanovic, line the walls of a modest clubhouse.
One shows a boyish Novak wearing a Partizan baseball cap and scarf, alongside childhood friend Ivanovic. Djokovic’s neighbour Djordjo Milenic says he used to tell grandfather Vlada that Novak “should marry her”.
Another shows Djokovic at 16, wearing the club’s black and white stripes as he concentrates intently on gearing up a double-handed backhand, a shot he has since honed into one of his most potent.
The clubhouse is being given its annual lick of paint on the day we arrive. Chairs and tables are stacked in the middle of the room while dust sheets cover the windows.
Dragan Gavrilovic – one of the members responsible for maintaining the 75-year-old club – is more than happy to down tools and talk tennis.
Pulling out a cigarette with white emulsion flicked over his fingers, he says: “When Novak was still small, from about 12 to 15, he used to come to play here and people from all over the city came to watch.
“They knew – and we knew – he was destined for big things. Everybody wanted to see him. They wanted to see history being born.”
Back in Banjica, behind his old apartment block, a colourful mural shows Djokovic flanked on one side by the patriarchal grandfather he doted on, childhood coach Jelena Gencic on the other.
Locals wander past without blinking an eye. Some may not even realise Djokovic lived there, but not many.
A woman sweeping up leaves and dirt outside the one flat which has a garden stops to speak with us. “Yes, you should write about Novak, you should,” she says.
“He’s like from heaven. He’s not human, yet he is a modest, normal guy.”
She has lived here for 40 years. She points to the concrete football pitch behind us, where a few stray dogs are sleeping in the sun.
“That’s where he used to play football. When he had time, of course, because he trained so much.
“Then he became famous, but he would still come here as often as he could, if it was for one day or five minutes.”
The woman is reluctant to give her name and disappears back into her yard saying she doesn’t want to talk any more.
But she returns a few minutes later, clearly unable to stop herself sharing the pride and love she has for Djokovic.
She was one of the many who spent nights down in the basement bomb shelter. Once that subject comes up, she retreats again.
“Let’s not talk about that,” she says. “It’s not nice to talk about what your neighbours did in such a delicate time.”
Yet she adds: “When we were there I told the younger ones to run, to leave the country. At that time we thought they will not bomb the civilians. But they did.”