My French teacher apologized the other day, stopping in the midst of the article we were reading about the implications of the recent elections in Belgium, to express her regret that she had slipped into using the familiar "tu" form of the word "you" with us, rather than the more formal "vous." Did she get a lecture from her superior? Or did she just wake up in the middle of night and cringe with shame at the realization that she had slipped into the territory of family and friends without asking permission to do so?
My classmates, thankfully, had the same reaction as me. No problem. After all, we've been with her for almost two years now. She's warm and friendly and does her best to decode the mysteries of French politics, culture, history, whatever, answering a million silly questions, always with good humor. So no offense taken.
My default position has always been to use "vous," as a safeguard against offending anyone with whom I might be talking. I always just figured that it's a better bet to be on the more formal side. But there's a trap. You should never "vous" a child, for example. And yes, I'm the idiot talking to the two year old like he's a professor or something. But even more importantly, once someone starts tutoying you, you really don't want to create the impression (by your continued use of "vous"), that you want to maintain a respectful distance. It can be kind of like saying, "I don't really want to be your friend." And that's certainly not a message I want to be sending.
Sigh. Some day, I'm hoping, this will all be second nature. Just not yet.