Not saying ‘bonjour’ is a cardinal sin in France. Before we moved to France, we were on holiday in Brittany and needed to see a doctor. I went into the waiting room while my husband went to do a bit of shopping and find a parking place. There were about 8 other people already there, so I took a magazine off the table. The next person to enter said ‘hello’ to the assembly. The following person went round and shook everyone’s hand including mine, as did everyone else that entered. I had never felt so impolite in all my life. When my husband arrived, I whispered, “Say ‘hello’ to everyone”. He turned to the crowd and did a nod and a general, ‘hello’, but to no one in particular. I knew that this was not enough. I had learned my lesson and made sure I said ‘goodbye’ politely to everyone as I left.
I once had a student who worked in the Tourist Office. She thinks that everyone who is not French is impolite because they don’t even say the important ‘hello’ before launching into their enquiry. Even if you say, “Excuse me, please could you be so kind as to give me some information?” and you smile brightly, you will still be classed as impolite because you did not start with, ‘bonjour’.