I, too, was a few years too young to be a hippie, but I witnessed the movement as a young teen. They created a large social revolution in the country.

IMO, the "free love" was a protest of the societal expectation of virginity until marriage, and the reality that many young people were coming home from Vietnam in body bags.

The only STD that I recall was V.D. which was treatable with penicillin.