Americans, a subway is not a subway. If you go down some stairs next to a sign that says SUBWAY, you are simply going to go under a street and back up to the other side of it. You are not going to catch the next train to Piccadilly Circus. If you want to get a train to go there, look for the London Underground sign. Of course, subway tunnels under streets are a very good idea because the British drive on the wrong side of the road!
When you check into a hotel, ask for a short lesson about the bathroom. No two of these in Britain are the same. I usually have to look around for several minutes before I can figure out how to flush the toilet. And I can almost never operate the shower without instructions. I once had to get out of a shower in Oxford and go downstairs to ask the hotel receptionist how to turn it off. There is actually a postcard called The British Bathroom, with everything on
it labeled to help tourists!
Seriously, though, if you are going to travel to the U.K., or to any as other foreign country, spend some time learning about it before you go. Your trip will be much more fun and less stressful!