What made the people in world war 1 start war?

Some @sshole who had a stupid moustache decided to (against all logic) visit some place in Eastern Europe where he knew he could be assassinated, and in an open-top car no less. The assassins were organized into a group with a cliche name (Black Hand), and had managed to make an intricate assassination plot that consisted of "just kill this dumb@ss." The first fagg0t threw a sh!tty 1914 grenade that took ten seconds to blow up, and thus Ferdinand (the @sshole) just drove away without noticing it, then had noticed the explosion that was far away from them by then. Franz F@ggot@ss then decided to visit a hospital where the grenade victims were, and his driver happened to take a wrong turn at Albuquerque and then an assassin who had the munchies was eating a sandwich in a nearby cafe noticed the guy, then ran out and shot him. So yeah, a sandwich caused the Holocaust, nuclear bombings of Japan, Cold War, Vietnam War, and hippies. Blame Gavrilo Princip and his goddamned sandwich.