There are anywhere between 100 and 500 BILLION galaxies in the observable universe. In EACH galaxy, there are billions or even trillions of stars. Orbiting many of those stars are planets, meaning there are millions or billions of planets in each galaxy. There is a good chance many of those planets are capable of harboring life. Add it all up, and how could extraterrestrial life not exist, amirite?

So true. When I was younger, I conflated the two as well. Whenever I'd hear the term 'alien/extraterrestrial life', I'd assume they meant intelligent life. Which of course is a mistake.

I think there is an abundance of highly intelligent, spacefaring life out there, but we may be spread too far apart to communicate with one another. Remember space is immensely vast. To make contact with another intelligent civilization we'd have to overcome the boundaries of space and time itself, which may or may not be possible. Really tickles your noggin.