American writers often say they find it difficult to write Superman. They say he’s too powerful; you can’t give him problems. But Superman is a metaphor. For me, Superman has the same problems we do, but on a Paul Bunyan scale. If Superman walks the dog, he walks it around the asteroid belt because it can fly in space. When Superman’s relatives visit, they come from the 31st century and bring some hellish monster conqueror from the future. But it’s still a story about your relatives visiting.
Other quotes from Grant Morrison.