Being in a country as a transit destination (in our case from New Zealand to Thailand), I like to have it as easy and comfortable as possible.
Not worrying about anything, until the connecting flight arrives.
But it's not working in Australia. After changing the money with a goal to get some coffee, you get metal coins.
Intuition and rules of usability dictate that the bigger coin is the more important one.
Alas, that is not true. Meet the reverse rules of "only god knows why".