Well except that there are those who DO know what fibromyalgia is. (When it's real, which is not 100% of the time.)

It's a corn allergy. (Or sometimes another food allergy.)

Those who find their allergies and get _completely_ off of both their allergy(ies) and _all_ processed foods with hidden ingredients eventually find they don't have it anymore. Because you're part right, the disease actually doesn't exist... but at least _some_ of the time the symptoms actually do.