Last Night I had the Strangest Dream...

So I had this bizarre dream before waking up this morning. I was riding the London Underground. Well, it was sort of hard to tell, but for some reason I knew it was. The platforms, though, were much more like the regional rail platforms here. Anyway, I got on the train. Or at least I thought I did. I then found myself running along the train, from station to station, trying to get on. Eventually I did. The train pulled into a station, and I may or may not have seen a green sign indicating trains to Lechmere (the terminal of the green line in Boston). The train then pulled out of the station in the same direction it came in, but went on different track (only in my twisted dreams would a station be built on a wye). The other thing is that the big appeal of the train ride (at least for some people) is that they were broadcasting a live Pink Floyd concert on the train loudspeaker system, apparently this was some big annual event. It was very strange, and I'm not sure what to make of it.