The Ultimate Question

[Pokerface]

This is a question I'm sure everyone at some point in their lives has asked themselves multiple times. I've heard comedians try to explain it but there has to be a logical/realistic explanation for this phenomena. I've racked my brain numerous times and I cant arrive at a plausible conclusion.

When you are driving why is it that you always see a single shoe laying on the side of the road?

[VladtheImpaler]

Because the serial killer always keeps one as a fetishy memento.

[Kybosh]

From personal experience, it's infinitely funnier when you only throw one shoe from your passenger out the window.

[malcolmk14]

Did you see the one on 9th Ave coming into downtown today too?

[Poison]

I must be reaaaaaally slow today, can someone point out the punchline for me????