The Mysterious Parasitical Running Man

Recently when I've gone running at the causeway in the morning, this local guy has run with me. I don't know who he is and he has never spoken to me. The first time he ran with me I tried to throw him off with some quick turn-arounds and stuff, but he stuck right with me.

Back then I considered it annoying. I enjoy my private time when I run and he also screwed up my pacing. But now I realize that he doesn't speak, so I still get my private time and he is pushing me to run a bit faster.

The only clothes he wears is a pair of shorts. No shirt, shoes or anything. I can't imagine running on that rough concrete barefooted. I wonder why he has latched on to me? Am I his inspiration to exercise? Is he mocking me? Who knows?