A thought I had, careening in a taxi towards the Buenos Aires airport on my way home from Wikimania…
Driving a vehicle is rather like understanding conversation. Knowing the (explicit) road rules is not enough. You need to understand the implicit rules of driving in practice — what you might call the traffic rules. How much space do you leave? Where are lanes and how do they work, especially when changing? What does tooting the horn mean? Is the speed limit strictly adhered-to or just a suggestion? How do you expect larger or smaller vehicles to behave?
You might think you just learn this once, and you’re done… until you experience driving in another country. Then you realise how much implicit knowledge you had about traffic norms in your first country.
Now the only place my analogy seems to fall down is when it all goes horribly wrong. If you get the road or traffic rules wrong, you will notice. :) But conversations can go horribly wrong without similar warning signs. For example, you could walk away from a conversation thinking, “That person is unbelievably RUDE! How could they think it was acceptable to behave that way!” when in fact they were unaware that the two of you had divergent conversation rules. If either of you had figured this out earlier and self-corrected or corrected the other, the flow could have been righted and continued without dragging a burning car-crash of a conversation behind it.

Or city even!
(Still not used to traffic in Melbourne)
You’re absolutely right about conversations. Even in anglo-Australia, where we are fed media from both the UK and the USA, and have imported so much of their cultural standard there can still be lots of subtle miscommunication. More than once I’ve stopped mid-conversation with my English and American counterparts staring at me to think “ok, what did I just say?”.
— Danielle · Sep 14, 13:33 · #