I've always wondered how people believe something is working for them even in the face of substantial evidence showing it's useless. My initial thought is that it was simply selective hearing, or just stupidity. Turns out it may be more complicated...
Rethinking the Placebo Effect: How Our Minds Actually Affect Our Bodies | Brain Pickings
Rethinking the Placebo Effect: How Our Minds Actually Affect Our Bodies | Brain Pickings