Except it does correlate meaningfully, don't believe me? Break your index finger, does it hurt? No shit.
That's not to say the nervous system can't create pain that has no source, the entire condition of fibromyalgia is evidence of that possibility, but to say they aren't meaningfully correlated is insane.
Most people who have pain unrelated to medical diagnosis in their 30's and 40's are fat as hell, eat like crap, and get no exercise, and are constantly dehydrated. That's why they hurt so damn much.