I'm not sure what you mean by placebo; yes, your mind creates the experience, if that is what you mean, but that is precisely the point. Sitting in a dark closet is not at all the same--it is the floating aspect that makes it different. Sitting you become aware of all the points where your body is in contact with the floor. walls etc whereas floating takes away any sensations. For me it was a hallucinogenic experience--less about thoughts than visuals. Like Mysterie said, I'm only sorry they have to cost so much.