Djokovic won his first Grand Slam in 2008 and he has been proving over and over again for 17 years that he's the greatest tennis player of all time. That must still drive some people crazy. Under normal circumstances a player his age should've retired long ago, yet here he is reaching his 19th Wimbledon semi final. You don't even need to be a tennis expert, anyone with the slightest knowledge of the sport knows how important Djokovic's place is in the history of tennis.