Lot’s of things were going on in the 70’s. The peace movement, people living together in collective housing, higher sexual freedom and more flexible sexual identity, generally rebelling against authorities, cannabis becoming popular. All this was also expressed in art, music, paintings and movies.

In UK this may have been further emphasized by a very backwards school system, with many attending boarding schools and wearing uniforms.
Something I remember when attending public school in Denmark in the 70’s as extremely backwards compared to conditions here.