don't move up the aisle when there clearly isn't any way people are going to be able to fit on the train otherwise.

I don't get it- people are generally polite when it comes to moving out the way, or stepping off the train temporarily to allow people to get off, but they have to be cajoled with a "can you move up the aisle please" every time this happens. And they sometime ignore that unless someone says it a bit closer to their face. Odd. I don't think it's even twats but just part of the human condition.