"If you're going / to San Francisco / be sure to wear / some flowers in your hair..."
Peace, love, hippie stuff... That antiwar demo, where the protester sticks the stem of a flower down the barrel of a Guardsman's gun... Groovy... Summer of Love, man...
It got co-opted by The Man: admen used the imagery/language to sell you stuff; The Mob, with no sign of conscience, sold bad drugs. Feh.
But what's so funny 'bout peace, love, and understanding?