Arran, it's all code to make sure you outsiders have to work at penetrating the culture and not coming across as a new chum.

But you reminded me of my favourite Irish joke, where your man visited a trick cyclist and asked "What would I be if I had an IQ of 180?"
"Ah, you'd be a psychiatrist, for sure."    [A reasonable punch line on it's own, actually.]
"And what would I be if I had an IQ of 120?"
"Oh, you'd be a univerrsity student."
"Really? And what would I be if I had an IQ of 60?"
"Don't be daft, man! You wouldn't be able to tie up your shoelaces or do up the buttons on your shirt!"

"Oh!" said your man, and thought for a moment.
"I've often wondered why Australians wear T shirts and thongs."

Cheers, Rowan