One question (tangentially related to this topic): I have been asked a number of times, both in the UK and particularly in Australia, by people from the US (whom I have usually met because of work, though occasionally they have been tourists) about when to tip (in general), or should they tip in such-and-such an occasion, or how much they should tip.

I give the answer –.but then they don't believe me and proceed to tip even if the answer has been "no, no need to tip in this setting", or else they give a wildly inflated tip that is totally inappropriate in the setting (nobody in Australia, for example, would ever dream of leaving a tip in a restaurant of 20 per cent: it's so much and so excessive as to be embarrassing.

So my question is: given the fact that these people have asked the question in the first place indicates that they are aware that tipping practices may differ from what they're accustomed to at home – why ask if they're not going to act on the answer?