I'm a great believer in catchphrases and standing jokes that are repeated endlessly.
There's a guy in the ticket office down at my local railway station who always greets passengers with a cheery "Evening", whatever time of the day it is. Regulars get used to it, but it will always catch out the odd newcomer.
I thought for a long time that the party piece was reserved for customers. Recently, however, I observed the ticket man arriving on shift at lunchtime and saying "Evening" to his colleagues. It's his way of making the day go that little bit quicker and all power to his elbow. It reminds me of the shop floor at Grace Brothers:
"Are you free, Mr Humphries?"
"I'm free, Captain Peacock."
"Are you free, Mrs Slocombe?"
"No I am not free, Captain Peacock. I was up all last night with my pussy and cannot possibly go to Mr Rumbold's office now. And I am unanimous in that..."