Some people live in two worlds; others live in one.
Two-world people imagine a utopia, where all is perfect. They think about this ideal world so much it becomes real to them, but it is clear it’s not the world they live in. Then, they also see reality, which they view as far from perfect. They live their lives comparing the world as it is (or as they see it) with the imaginary perfect world.
One-world people do not imagine a separate, perfect world. They only see one world, with good and bad, and rather than comparing it to another world they just deal with it as it is.