Do you know what blows my mind?
From Astronomy Picture of the Day, this is a Hubble telescope image of the Sombrero Galaxy.
OK, so, it's not all that fabulous, but think about this. In our sky you can see lots of stars in our galaxy. Our galaxy is huge. And then, also in our sky, you can see whole other galaxies. They are so far away that they are, like, the same apparent size as stars.
It is just freakin' amazing the range of orders of magnitude present in our universe. It reminds me of this, of course (from Monty Python's The Meaning of Life, which I remember seeing in the theater in New Orleans as a little kid, with my mom and her friend and her friend's kids):