Turn Here

I went hiking today. I was supposed to meet some folks to join on the hike. One of them just said "meet us at the big stone." I was embarrassed to say that even though I thought I know my way around pretty well, I didn't know where she meant. She proceeded to give me detailed directions to the road the "stone" was on. I asked "how will I know the stone?" She said, "you are a medical student; You'll figure it out. I finally did.