If our Milky Way galaxy and the universe at large are indeed teeming with intelligent extraterrestrial (ET) civilizations, why haven't we seen any sign of them yet? In other words, where are they? This mystery has become known as the "Fermi paradox."
Unless we as a nation "grow up" emotionally and intellectually and deal with our serious problems rather than through "denihilism," future generations will look back at us and curse us for our ignorance.
We don't see any evidence extraterrestrial life. Does that mean that Homo sapiens is the smartest species within 100 thousand light-years? That would be remarkable and, judging by my daily interaction with said species, scary.