The world is full of little mysteries. Like, where did all this ink on my arm come from? It's a big splotch that I must have picked up from a flat surface. But I don't see any ink on any flat surfaces and none of my pens appear to be leaking. And anyway, how on earth did I get ink on just that one spot on my arm and not all over my hands and my face and my clothes?
It's a mystery. See, life is exciting!