Edges

I don't know exactly where my edges are. Maybe they're just over the end of my patience. Maybe they're more distant and less visible. But I know they are there. What I don't know is what I'll do when I go over them. What happens when the edges are behind me, or above me? What happens when I've run past the edges and can't get back? I don't want to learn when it's too late. But I may not want to learn too early.