I love your example of a cup of water from the ocean and no sign of fish in it!
It is quite plausible that life in some form or the other surely exists somewhere in the universe apart from that on Earth. Considering the size and the vastness of the known universe, we are just an infinitely small pixel in an infinitely huge, infinitely high resolution, multi-dimensional display (so-to-say), 60 years in space is less than a mere dot on the timeline of the universe!
Their intelligence is a different debate altogether!