Is This Your Card?

Every once in a while I’ll find a single playing card, lying by itself on the sidewalk, usually face down; and I’ll pick it up to see what it is.
     Don’t you?
     For a few years I seemed to be having a run of sixes; I’d find a card, flip it over, and as if by magic another six would appear.
     And because I can’t remember ever losing any cards myself, I wonder where these could possibly be coming from. Who removes a single card from a deck and takes it with them on a walk?
     That same magician, perhaps.