First, every patient has very valuable knowledge for their physician: their symptoms. There's absolutely no substitute, and as a patient you are the definitive source for that information and the undisputed expert.
Second, I do find that it's very often helpful when my patients have done some reading about their condition. It shows engagement in their care and is a great way to jumpstart the conversation. And it gives me a good idea of the level of insight into their disease and the best way to approach the patient education part of my task.
However, to be clear, it is my responsibility ethically and legally to have the expertise to treat you and to apply that expertise in making an assessment and plan. If I find that I don't have the expertise that's necessary, I should be consulting with or referring you to another medical professional who does. It's your right to have your physician's thinking explained to you and to agree or disagree with the plan, and if you think your physician is wrong, it's also your right to ask for a second opinion. However, it is never ethical for me to rely on your medical judgment in formulating a plan.
So, please don't take it the wrong way when your physician limits the amount of research he or she will hear from you. I stick to strict boundaries even with patients who are physicians themselves--even when they are significantly more senior and experienced. And when I'm the patient, I try my hardest to describe only my symptoms, confident that I will receive better care that way.