When making a piece of furniture for a Park Lane, Hotel, I queried a dimension given by the Chief Engineer (Irish) as it was way off. He replied "when I was at school they were changing from imperial to metric, so I never learnt either"!
A few years ago I was turned down for a knee joint replacement as my BMI was too high, the my medical centre had stated that I was 178 Kg (I am actually 103Kg). When I found out, I told the GP that if I was that big I would not get through his door! My guess was that a nurse could not calculate stones to Kg.