head shop

The Pursuit of Happynessの主人公は大人になりました。
After coming out of the military, where everything had been about discipline,   process, order, and structure, I experienced the city that celebrated individuality and nonconformity above all else as if I was actually visiting a foreign country. My favorite stomping grounds became Haight-Ashbury, once the cradle of sex, drugs, and rock 'n' roll, still jumping with music clubs, restaurants, bookstores, head shops, and a crazy street scene that was colorful and alive.
"head shops" どんな店なのか全く見当がつかないので辞書を見ます。
・Vocabulary.com: a shop specializing in articles of interest to drug users: "he bought some roach clips and hashish pipes at the head shop”
・Wiktionay: A retail outlet specializing in sale of paraphernalia related to consumption of cannabis, other recreational drugs, and New Age herbs, as well as generally selling counterculture art, magazines, music, clothing, and home decor.
何故 "head shops" と呼ばれるのか、ドラッグ自体は売らないのか（裏では販売している？）疑問が残りますが、深追いは止めておきます。