One of my pet phobias is large objects. It's not exactly a phobia per se, but more of a slight shiver that runs down (or up?) your spine for a fleeting moment and you quickly think of shining happy thoughts to distract yourself. I think this had its genesis in the movie The Independence Day in which, if I remember correctly, a spaceship a few miles in diameter fills the sky above Washington, DC.
Now just imagine that it's not a spaceship, but the planet Jupiter, and that it's not a few miles in diameter, but is 71,492 fricking miles from one end to the other, and is so big that your entire sky is but a closeup of the planet's terrain.
You don't have to imagine this, actually. You can see a simulation video.
Sweet dreams, here I come.