I’m very fond of quoting a comedy sketch by the British comedians Peter Cook and Dudley Moore. Moore is interviewing Cooke, who is in the role Sir Arthur Streeb-Greebling, the proprietor of a very unsuccessful restaurant.
“Have you learnt from your mistakes, Sir Arthur?”
“Yes I have, and I am confident that if asked, I could repeat them all perfectly.”
I normally use this in mockery of politicians who are fond of saying “we must learn from our mistakes” after any disaster or administrative failure. But having just this moment replicated a very difficult to replicate bug, and done it more easily the third time I tried, I think I shall add this to my repertoire of testing techniques!