My first trip abroad was a day trip by ferry to Boulogne with my mother when I was ten. The photograph above was taken by my mother from the ferry ('Maid of Orleans', I think) as it docked at Boulogne. The picture shows a diesel railcar waiting to speed passengers away. We stayed in Boulogne looking at the town and the docks. We had lunch at a small restaurant in the town, sitting at one of the outside tables - this idea of eating outside struck me as very continental.
Later, we returned to the docks for our return sailing where I watched the Paris express being marshalled by one of the exotic-looking '231' Nord Pacifics. I'm sure my mother took a photograph of the '231' but I'm afraid I've not been able to find it.
I spoke no French, but my interest in railways must have been apparent because at one point one of the shunters suddenly lifted me up into a baggage car where I sat on the floor as the train disappeared towards the station throat. My mother did not at first realise that this was only a shunting move and envisaged me ending up in Paris! She was relieved when the train stopped and reversed into an adjacent platform where we were reunited. That was my first trip on a French train. At the time, I found it perfectly natural to be suddenly given a short ride on a train in a foreign country - it's only looking back now that it seems remarkable.