If you Humans have all this technology why haven't you colonized the moon yet?
But what do you mean by colonisation?
We have already gone there and left things on the moon, scientific instruments on the moon help us understand many things about the moon.
Because after we've been to the Space and the Moon, we've realized we don't need to do that ever again. Flying humans to space and maintaining their life support is expensive as all hell. If we want to explore or get samples or something, we just send a robot to do it - it's faster, cheaper, easier, and a hell of a lot safer.