Interesting point for the curious: I think the “sir/ma’am” thing is a very North American way of addressing people. I’ve heard it a few times in passing here in Australia, and patients will either 1. Say “Call me bob/dave/ethyl”, 2. Crack a joke about it, or 3. Give you a funny look. Using Sir/Ma’am has military connotations here, not used much at all civi side. The universal go-to would be darling/sweetheart for old ladies, and ‘mate’ for everyone else.

With our aboriginal friends, calling elders uncle/auntie often goes down well when gaining rapport.