Just because the psychedelic journey takes place entirely in one’s mind doesn’t mean it isn’t real. It is an experience and, for some of us, one of the most profound a person can have. As such, it takes its place as a feature in the landscape of a life. It can serve as a reference point, a guidepost, a wellspring, and, for some, a kind of spiritual sign or shrine. For me, the experiences have become landmarks to circle around and interrogate for meaning — meanings about myself, obviously, but also about the world.
—Michael Pollan, How to Change Your Mind, Allen Lane, 2018