“This has been a great opportunity for improvement”… normally said after something has gone wrong.
I would sometimes get stares of incomprehension when I used the expression “busier than a blue arsed fly”…
I was talking to a fellow from out east and he said that his expression is similar but adds further context “busier than a green arsed fly around a piece of shit” which is certainly easier to comprehend.
I get a chuckle that that the arses of the flies in Australia were blue, but in Canada they were green…