How do ordinary people become revolutionaries? In 2000, too-cool-to-care Belgrade rock kid Srđa Popović found himself at the centre of a movement which was about to change the world. Popović was one of the unexpected leaders of the student movement Otpor! that overthrew dictator Slobodan Milošević and established democracy in Serbia all by avoiding violence and opting for something far more powerful: a sense of humour.