I'm American, but it seems to me that when I’ve encountered [Australian speech][1] or writing, I didn’t have much trouble understanding it. The words are mostly familiar to me. So what’s going on in [Waltzing Matilda][2]?
 
An excerpt:

>Once a jolly swagman camped by a billabong   
Under the shade of a coolibah tree,    
And he sang as he watched and waited till his billy boiled:   
"Who'll come a-waltzing Matilda, with me?"  
  
Chorus snippet 

>Down came a jumbuck to drink at that billabong.   
Up jumped the swagman and grabbed him with glee.   
And he sang as he shoved that jumbuck in his tucker bag:   
"You'll come a-waltzing Matilda, with me."     

I think that a typical American reader or listener will understand almost nothing of the story without discussion. 

Was it deliberately written with a lot of Australianisms? Or does the use of a lot of Australianisms reflect something about social class, the way Cockney English would? Do Australians think it's funny because of this quality?


  [1]: http://www.smh.com.au/federal-politics/political-news/transcript-of-julia-gillards-speech-20121009-27c36.html
  [2]: https://en.wikipedia.org/wiki/Waltzing_Matilda#Lyrics