A curious part of Rickson Gracie's memoir tells of an early TV commercial for Gracie jiu-jitsu. The setting is a beach in Rio de Janeiro, where a skinny dude (played by a young Grandmaster Robson Gracie) is hanging out with his girlfriend, until a bigger, muscular guy shoves him. Seconds later, the girlfriend accepts that she is the bigger guy's girlfriend now.
Skinny Guy then decides to learn jiu-jitsu. Months later, he comes back to the beach to find his former lover still with the other guy, presumably because no one shoved him in the intervening months. Skinny Guy approaches, Muscle Guy gets up to kick his ass, but this time Skinny Guy has enough knowledge to break the brute's arm. Needless to say, the girlfriend is now his again.
Judging from Robson's age in the footage, the commercial seems to be from around 1955, just four years after the start of the age of Brazilian television; and although this copy is cut off before the end, it's most likely an ad for the original Gracie Academy, founded in 1925 in Rio. If you know someone who's not convinced they should start training, show them this. After all, as the narrator warns, cases exactly like this happen by the thousands.