I used to spend 2 hours each day travelling the underground when I worked in London.
Its true, the map they give you is very misleading. I have sometimes found that routes that may seem direct on the map take you round the houses, and back again. You could probably walk it in quarter the time.
I used to get on the tube that led from Heathrow airport to the city, it was always full of American, Japanese, Canadian and various other tourists, in total confusion most of the time trying to work out where they were going, boy did they look lost.