Note 1

Deep down I believe we're unique.  By definition, that would also indicate that the concept of alien life may be exactly that—just a concept. In fact this appears to be the recurrent theme, here. Everything we think we know about ourselves and our planet are just concepts. And then there's the real world awaiting us to discover it every remaining moment of our lives. 

Because according to my belief—all life in the cosmos is, by definition, connected—everything in this universe including ourselves are one and the same; and furthermore, a fraction of the continuing whole.  Both of the terms 'alien' and 'extraterrestrial' are quaint presuppositional phrases in this context, that in a sense, lay their card down on the tabletop before later being trumped by the discovery that all life in the cosmos remains interrelated.  Now if perusers of the originally intended concept of 'alien' want to point out that its a matter of semantics, this is where the argument gets well underway. 

Here we are, isolated humans, attempting to examine the skies grain by grain, under a magnifying glass, for signs of alien life, and the most peculiar thing, it's not so much that the situation begs to be compared with looking through the wrong end of a telescope, but more to the point, we are the alien in such an elemental and real way, that it escapes the majority of humanity, the very idea that we may be, after all, fundamentally alone in the universe, in various inescapable ways. It doesn't make a difference if we should turn out to be the solitary example of life in eternity or if the cosmos is teeming with a myriad different species of the same cosmic clade of which we may only be an infinitesimal sub-specimen of, the outcome's the same; all living nodes of eternity may share this quality regardless.   

For instance, there could be thousands, nay, millions of isolated pockets of life spread across this ripening universe, this budding universe, this dying universe, this living universe, and for all we know—the essential nature of existence may in fact necessarily make these isolated pockets not only indispensably oblivious to each other's existence, but more to the point—they could be spread out across time while we mistake it for space—or the interstellar distances may be, in fact, too much for any species to breach because it turns out they described time after all. We remain challenged enough when it comes to having to recognize each other's humanity right here on Earth. 

So what does the word "unique" really mean, I wonder? 

I'm not sure, but I think I know what human means. It means having come from the humus of the earth—"earth form"—roughly, and this definition, imbued with the humility attributed to our kind, should be easily seen as befitting any and all sentient races that might emerge from their own respective planets. 

 I believe there must be additional life, even advanced, sentient, and civilized life, out there amidst the crowd of stars. But not until you subtract us from it. I don't believe for one second it would be any more alien than the iguanas falling out of the trees, here; or—for that matter—I could just as easily believe they are exactly just as alien as them.

In any case, it appears to me that if such additional species were to exist, I don't necessarily think we would be intended to make contact with one other, necessarily. What a silly idea. Something about it seems to fly against nature itself, and I don't know why.    

I think if there are isolated pockets of life strewn across the universe, they are isolated from each other for good reason. Merely to be left alone would be of sufficient cause.