Two machines were out of order at work today. When the technician finally arrived, late, not rushing, not fussed by the boss shouting at him, he fixed one machine almost by slapping the side of it. He then said how he did not fix what was not broken and always did the least possible to make things work.
He then found a number of errors on the 2nd machine and when the young operator said in a worried voice "Is it user error?" the technician replied "No (smile) not user error, but certainly not user competence"
At these words the young operator was greatly relieved and walked away happy.