Yes it is important to know past history events because if no one taught the world history we wouldn't learn from the past to make a more advance future.
Say it all started with cave men, they didn't know a clue about the world. Yet they found how to eat, fight, hunt, survive, ect. But if no one taught each other or their next generation it would basically be like starting all over again and again. History would repeat itself and would never accelerate to something more advanced.