The night train from Paris to Venice was about to leave when I heard the noise in the corridor outside my sleeper: loud American voices and the banging of baggage against the carriage walls.

A woman carrying a small child and a large suitcase, and an older woman who was obviously her mother, appeared at my door. The older woman was also laden with luggage. They hauled their heavy cases inside and only then spotted me sitting in the corner.

They were alarmed.

This was a six-bed sleeper and they assumed they would have it to themselves...