Humans are strange. Given the infinite vastness of the universe, wouldn't it be the height of vanity to consider ourselves completely unique beings? That only one Earth could happen?
When They arrived, we were stunned anyway. We were united in fear, and then in celebration. And we shouted to Them:
And when they finally established contact, they did so in a poorly-synthesized voice and clunky dialect: "Y'all gots ain't no call to cuss at us. Dang. Damn, y'all." And they left, never to conquer, but also never to befriend.