Peter Mayle towards the end of Toujours Provence offers some observations about two expressions that serve phatic functions and then some:

Depending on inflection, ah bon can express shock, disbelief, indifference, irritation, or joy -- a remarkalbe achievement for two short words. Similarly, it is possible to conduct the greater part of a brief conversation with two other monosyllables -- ça va, which literally mean "it goes."

Same ingredients, countless preparations. It is the same ethos that pervades Mayle’s description of table talk or rather talk at table:

There is something about lunch in France that never fails to overcome any small reserves of willpower that I possess. I can sit down, resolved to be moderate, determined to eat and drink lightly, and be there three hours later, nursing my wine and still open to temptation. I don’t think it’s greed. I think it’s the atmosphere generated by a roomful of people who are totally intent on eating and drinking. And while they do it, they talk about it; not about politics or sport or business, but about what is on the plate and in the glass. Sauces are compared, recipes argued over, past meals remembered, and future meals planned. The world and its problems can be dealt with later on, but for the moment, la bouffe takes priority and contentment hangs in the air. I find it irresistible.

Worth noting that being in a state still open to temptation is not the same as having succumbed to temptation.

And for day 10