The story
Reportedly originated from song lyrics for If 6 Was 9 (1967) by Jimi Hendrix and was popularized by its use in Crosby, Stills, Nash & Young's counterculture anthem Almost Cut My Hair.
Etymology from Wiktionary, CC BY-SA 4.0.
freak flag
Today it means: Unconventional or unrestrained behavior; extreme, nonconformist views; the side of one's personality which harbors a tendency toward such behavior or such views. Full definition →