Sometimes I'm not really sure if it is better to be a patient who is very knowledgable of their disease and similar diseases or if it's better to not know. It sounds odd but each end of the spectrum has it's pros and cons and I know each very well. Sometimes even a happy medium still has more problems than it's really worth, but you can't take back much knowledge.
Being a bit of an expert of my disease has lots of pros. I actually know what my doctor is talking about and can catch onto a lot of things before he says it. For example, last time I saw him he checked a bunch of tender points on my back and chest asking if they hurt. When he finished, I said "Did you honestly just check me for fibromyalgia?" "No- yeah, I did." And I'm aware of why he does certain things- for example, sending me for an EKG when my heart was beating too fast or why my kidney problems are such a concern. Knowing a lot about your disease also means you are aware of normal symptoms (to tell your doctor) and what might be causing it or what might help, and your more aware of things that are unusual and need to be told to your doctor.
The cons? Depending on your disease and yourself, knowing more about it might terrify you. Honestly, it's hard to get reliable facts and figures and what you see might not be true or might be rare. Listen to your doctor and go to reliable sources for information- especially foundation and hospital websites. Knowing the everything about your disease also means room for your imagination to wander a little- a fast heart rate from a brisk rate could begin to seem like inflammation. That sort of thing. It happens sometimes, it's common and I'm guilty of it. Not everyone does it or will, but it's human nature.
And what about the pros of blissful ignorance? Getting to leave the medical stuff (mostly) at the hospital. It's two different worlds, and what I would give to have that. Not knowing as much may also make it seem less scary. I don't have a lot for pros because some others don't apply to everyone, but even then I think the first point is amazing on it's own.
The cons are powerful too. You might be more scared because you don't know what's happening. It might be dangerous in an emergency when you can't explain something. You might not know if a side effect or symptom is worrisome, and might not call your doctor. And you may not catch something the doctor says, which could be dangerous.
I think the best place to be is a happy medium. Though I know a lot know, sometimes I wish I didn't. But, it's what's worked best for me. You know what works best with you.