why does the english in the 50s sound so proper and cool?

Question

I was watching some instructional educational movies like molly grows up, and such about menstration and how things works. they use words like golly. "goll-ly!" swell, and queer meant weird or strange back then, not homosexual.

Answer 1

A high value was placed on education. Most of the people involved in this type of film would be actors and in those days every actor was well drilled in elocution and was expected to speak correct English without a regional accent. It was the fashion of the time. Nowadays people are encouraged to use appropriate local accents when acting, but background commentaries of the kind you mention would still be done without an accent. 'Golly" has gone out of fashion, although it was very much used then, and queer bore its natural meaning of odd, just as gay meant bright and cheerful. Incidentally, people used to use "queer" for feeling unwell. They would say "I came all over queer!"

Answer 2

Because it was. People knew how to communicate then; now not so much.