The shoe...

I often see the "shoe" on the side of the road when I am driving and I wonder how in the heck did it get there?
Why is it always just one shoe? Who lost only one shoe? How did it get there?
These questions about the road shoe's have plagued me for years. Anyone else wonder about the shoe's lying randomly on the side of the road?
I fantasize about why they are really there...like they are clues for the CSI people to find or some one was trying to smash that annoying bug and oops, they threw their shoe out of the window.
OK...so it is weird, but it makes me wonder everytime I see one.
Today I saw a Nike Shox...who would drop/lose/throw a $90 pair of shoes out the window?