The train I am on is stopping there because its running too late and its all change. I know (because I did it on the way down) that I will lug my bag down to the platform I am currently told the next train departs from, only to find with a few minutes to spare that the platform has altered. I will race up to the top, try to get from one side of the station to the other which as far as I can tell is near impossible, clatter down to the new platform with my big bag and cram myself on a train where I will no doubt not get a seat.
Great fun.