A slogan of the hippie generation of the 1960's and coined by the poet Allen Ginsberg which meant the power of passive resistance. There is a movement today called the flower power movement that seeks to stop the bullying of teens by the older generation,curfews ect.
A woman a guy has sex with not because she's hot or he's in love ect. but for practice to get better at it so he can have a lot of good sex with the hot women. Practice girls are needed and without them sex with the really hot women would be just so so. Most practice are teen women and most guys who make use of them are teen men.