As one who has dealt with this quite a bit, I submit the following: The form you fill out is called a "Medical History", so if any of the items on the list are documented in your medical history (i.e. you have seen a doctor and been diagnosed) then tell them about it. Otherwise, don't say anything about it; it's not part of your medical history.
As Tahoe said, it is important that you are healthy, but if a problem has never been serious enough for you to see a doctor about in the past, and the Navy docs don't find anything during your physical, then I'd say you're probably healthy.
An example from my medical history: I get seasonal hayfever for which I take over-the-counter drugs. When filling out my initial medical forms, I put it down (at the time it didn't really matter because I was not applying for aviation). When I began applying for a transfer to aviation, I was told not to mention any conditions that hadn't been officailly diagnosed (i.e. my hayfever). Of course, it was already in my records so there was nothing I could do about that. When I had my flight physical, the doc asked me a few questions, took an x-ray of my sinuses and chest, and cleared me. It turned out OK, but I went through a lot of unnecessary stress in the days before my physical, and I'll always have "hayfever" listed in my record.
I know this doesn't help those who have already been through the physical, but hopefully it can help others in the future.
