Australianisms & Regional Slang

when I was in primary school we once had a substitute teacher from america (or maybe canada? I don't remember exactly) who was confused by people using "heaps" to mean "a lot/lots" or "more than enough"

e.g. "there were heaps of people here yesterday"

or

"[pouring a drink for you] that enough?"
"yeah that's heaps, thanks"

I guess it's in the same vein as using "piles" or "loads" to mean the same thing