Some of us are attracted to each other. We can then become a solar system unto our own, but don't ask me who's the sun.
Some of us aren't yet ready to make first contact — because that civilization yonder there, as promising as it may seem, is still riddled with civil war. They need to sort out their problems first. And send some explorers over to meet you. Maybe then, an intergalactic treaty can be formed.
Some planets are fertile and ripe with resources!
Others have been strip-mined, said F-U you to the environment, or… are barren.
And when we can take the consciousness & soul of a person and put it in another body, well, that'll be like extraterrestrial colonization.
