As of now EVEN with our limited knowledge we can assure that there are (were) no two human beings alike. For that matter existence of two similar objects (any objects even in their lowest form of existence) itself is a highly improbable possibility. Of course, I am talking on gene to gene and atom to atom basis. My point is if there are this many of constraints in forming two similar objects with the limited combinations why we can’t expect that WE ARE UNIQUE. Let u be the creator and just compare the combinations (of ???) you have for the manufacture of a human body with that of a planet like ours(hey just consider the physical aspects, otherwise you'll end up in messing all kinds of things, and that’s altogether a different science). So just imagine how improbable it is to have two sets of similar conditions which caused to the rise of life in its present form. Finally my point is simple. "As long as u don’t expect the one very similar to you (again on gene to gene and atom to atom basis) in your very next door it is reasonable enough to believe that WE ARE 'THE' LUCKIEST ONES ON OUR OWN AND THE, OTHERWISE, LONE UNIVERSE (pack the string theory for the time being).