Re 'Doctor' and 'Mister'. I understood that the distinction dated back to the 18th century with the emergence of an academically qualified Doctor-class while the real meat-cleaving surgery was left in the hands of barbers and anyone else who fancied a go. The 'Doctors' refused to acknowledge (or admit into their exalted ranks) 'the others' and therefore 'the others' remained plain 'misters'.