I do both, actually. I've defended the Earth from multiple invasions in my dreams. I like seeing the universe and discovering new species and planets and stars. Not all of them are friendly. But world peace, that I cannot do. There are things that I cannot change or tamper with because it will cause time to fracture and everything will breakdown and the universe will end. I've done that, it wasn't a pleasant experience, so I try to only poke the things that I can change. Mostly.