But not this one: just a scribbled slip to give the dumpling guy. And where cards are used, you then have to remember to line up and get your refund after eating. Some places they're good only on the day of issue.

It's really hard to argue against the notion that life is easier in China these days if you can use your phone. And getting easier by the day.

(Using cash also usually means accumulating a messy pile of change and grubby small bills that somehow keeps growing over time, unless you make a real effort to manage it.)