I'm of the opinion that it's only a matter of when do we find signs of extra-terrestrial life. I just can't believe that as massive as the galaxy is, not to mention the universe that life only developed on one rock.
Agreed. And finding signs of life is different than finding something alive. Not only is the universe unimaginably big, it's also incredibly old - about 13.8 billion years. Entire civilizations could have evolved and gone extinct long before there was any life on earth, not to mention the millions of potential planets where life never made it much past single cell organisms.