2. People want to be guided
Everything we do affects our brain chemistry: the foods we eat, the movies we watch, even the thoughts we have. “Drugs” are no different; they’re just a particularly effective short-cut.
People who can moderate their mood from the highs of giddy happiness to the suffocating lows of depressing days will achieve a powerful, quiet state where they — and only they — can control how they feel. Nothing external.