The art of walking on air

I always find it puzzling when, during my meandering, I come across a shoe abandoned on the side of the street. Why is it there? What happened to the feet that was inside it? Why would someone leave a shoe on the road? They say that more often than not, after an accident, shoes are what is left behind. Something about the strength of impact or something. That explains, or could explain, the lone shoe left behind. But what about those? Lined there, properly, on the side of a theatre, as if someone was about to come back to pick them up? Was it a gift to a homeless person? Then why would he leave them there?

Admit it: you're intrigued.