There may well be 500 billion stars (suns) in our Milky Way galaxy. The average number of planets orbiting each star could be maybe 8 or more. There may well be 2 trillion galaxies in the universe.

There must be other intelligent life out there, indeed numerous different civilisations throughout the universe. But it could be that no matter how advanced the technology of any of them becomes, the various civilisations could be too far apart to even detect the existence of the nearest neighbouring civilisation. I find that thought a tad spooky, as though it had been planned and executed that way from 'seeding'.