Earlier quoted context omitted.
Knowing that life may be common is a lot different than knowing that intelligence is.
Yes, but the universe is so mind mindbogglingly vast. So many galaxies and so many stars! It just doesn't seem right that what happened here didn't happen somewhere else.
The chances of intelligent life existing outside Earth are lower than the chance of that same intelligent life speaking flawless Swedish. We might as well send some Europop records to space as signals to aliens.
"Intelligence" is a human invention created by humans to describe humanity. It only applies to humans and human-like beings.