If  I had chance to change the world I wouldn't change anything because I think the world is doing good right now and besides what if I change something that is really important, then it well affect the world in a bad way.
For example what if  I changed the something the world needed like police or the president then the world would just fall apart and wouldn't survive.If I had a chance to change the world I would not change anything, I think the wouldn't survive with my changes that I would make, it would just make the world more corrupt.