Went out for a brief pint with one of my new neighbours. Very nice chap and his girlfriend who is a Doctor in London.
We chatted and it turns out she gets the train / tube in to work everyday and has done so for about a year. She sees the same people on the train every day. She has never spoken to or smiled in recognition of any of the people she shares a train with.
British commuter etqiuette is going strong. It's not just me you know... I'm not being paranoid. You're just not allowed to speak on the train.