I spent a couple weeks in London during my senior year in college. Towards the end of my stay I got lost trying to find my way back to the tube. I ended up following a couple signs that pointed me in the direction of a "subway" which led me to an underground street crossing. So, instead of realizing my mistake, I walked through the thing four or five times trying to fnd a train station somehow hidden in it. It was only until I scared a couple of 10 year old girls when I asked them where the subway was, while we were standing in it, that I figured out what happened.