When Novak Djokovic was a child, he frequently woke to the sounds of raining bombs.

When Novak Djokovic turned 12 years old, he heard bombers fly overhead whilst he sang Happy Birthday.

The world number one was living in a small apartment in Belgrade, Serbia, with his parents and his two brothers, Marko and Djordje, as NATO jets targeted the capital.

It was the midst of Yugoslav Wars, and he was forced to practice tennis inside an empty swimming pool, which had been converted into a tennis court. Often the practice sessions would abruptly end as he ran into the bomb shelters to seek cover.

Djokovic explained that during the few months NATO was bombing Belgrade in 1999, the fear and exhaustion caused him to lose focus.

“Because we were waking up every single night more or less at 2, 3am for two and a half months,” he told CBS’ 60 Minutes in 2012.

“But the best thing about it… I always try to remember those days in a positive, in a very bright way… We didn’t need to go to school and we played more tennis,” he added.

He further explained that those few months were formative for his family, and fuelled his desire to be successful.

“[The war] made us tougher. It made us more hungry, more hungry for the success,” he explained.

Ever since he was a child, the 31-year-old knew he wanted to be the world number one.

Djokovic’s former coach, Jelena Gencic, has told stories of the young boy turning up to a summer training camp with a bag so neatly packed it looked professional.

She was working at a summer clinic in the ski town, Kopaonik, where the Serbian lived.

Since nobody in his family played tennis, it was fate that the three tennis courts in town were built across the road from his parents’ creperie.

“Nobody in my family ever touched a tennis racket before me, so there was no tradition whatsoever. I would have become a skier or football player or a regular student. But that is destiny in life. When something is meant for you, it is meant for you,” he told The Telegraph in 2011.

When he was 18-years-old, the tennis legend met his wife and the mother of his two children – Tara, one, and Stefan, three.

Djokovic said he was desperate to impress Jelena, “the most wonderful girl he had ever met”.

He spoke of their first date in a promotional short film series called Made By Moments for Jacob’s Creek in 2016.

“In my eyes at the time it was a very exclusive place to take her. I wanted to impress her so I took her to this place,” he reveals of the chosen venue.

“Well, no!” his wife interjects, “It was a sports bar!”

In a recent interview with ESPN, he explained that Jelena helps him to keep a work life balance.

“She helped me to identify the emotions and feelings of everything that is going on and understand the big picture,” he said.

Novak Djokovic has 15 Grand Slam wins under his belt, and on Sunday night, after beating Rafael Nadal in three straight sets, Djokovic became the first person to win seven Australian Open titles.

He is far from being a frightened boy in Belgrade.