A new Amazon documentary sees Novak Djokovic reflect candidly on the relentless self-doubt that has driven his career, admitting that despite his unprecedented success he still cannot feel content and describes himself as his own "number one doubter". The film also traces how his childhood in Belgrade during the 1999 Nato bombings shaped his resilience and on-court demeanour, offering rare insight into the psychology behind one of tennis's most dominant and divisive figures as questions about his eventual retirement continue to swirl.

At 39, Djokovic is level with Margaret Court on 24 Grand Slam singles titles, the most in history, having reached at least the semi-finals in six of the last seven majors and become the oldest Australian Open finalist ever in January. His wife, Jelena, says he carries "the burden that he's never enough", while Djokovic himself recalls fleeing bomb attacks as a child, queuing for bread and milk, and his father borrowing money from "the wrong people" to fund his early tennis training. He says these formative experiences, along with having to suppress emotions that later surfaced on court, built the mentality that fuelled his rise and continues to drive him despite having no "expiry date" in mind for his career.