Picking up on Bill's story - I still remember a restaurant (for what it's worth, in Bishops Stortford) which was a very bizarre eating experience anyway as it was an Italian restaurant entirely staffed with Chinese waiters (and playing Julio Iglesias music). I asked for the bill. Not an easily confused word, you'd have thought. The waitress nodded and smiled, and then stood next to me for the next few minutes until my dining partner returned from the Ladies. Mary said "What's happening?", looking at the waitress standing next to me. I told her what had happened and she addressed the waitress herself, speaking slightly louder than usual and asking again for the bill. "Oh yes", said the waitress, and went to get the bill for us. I'll never know what the waitress had first thought I'd wanted.

As to different customs - when I returned from living in France for a couple of years I realised how many levels of good manners were built into the UK way of life, from crossing the road (I would cross when there was a gap in the traffic, whatever the crossing lights indicated) to queueing (my internal button to alert me to a queue appeared to have stopped working), as well as speaking up about poor food being served. Friends would move away from me each time I committed a faux-pas!