Quite a variety of answers here.
I’ve gotten that from Americans, usually followed by some bizarre mélange of Bostonian English and Dick Van Dyke from Mary Poppins as they tried to impersonate me.
As we say here: “Yeah… no.”
Slightly miffed, but more at the other’s unfamiliarity with Australians than at the comparison. Normally.
In fact, my good friend George Baloglou, Greek who worked for a long time in America, used the confusion in a way I found flatteringly insightful. He was describing me to a third party in Greece, and he said:
“Picture a guy who looks like a typical Greek greengrocer. And is culturally British.”
(The author, 1993)