Especially on #2. The sheer size of the galaxy is so mind-boggling. So many stars, and each one could potentially have some form of life on a planet around it. And it's just one galaxy of billions (or is it trillions? I forget, but it's already so huge that it hardly matters). So far away that we can hardly conceive of the idea of ever going there. But wait, it's already coming to us! More quickly than any realistic form of propulsion we could come up with.
