Hi wiz,
It's not at all uncommon for diabetes to be discovered randomly. In my own case it was found purely by chance when I had a blood test for something completely unrelated. At the time of diagnosis I was fit and not overweight, I had experienced no symptoms and have no family history of diabetes.
I think that when people start to suffer the classic symptoms, their blood sugars are generally way above the levels that mine, and probably yours, were when diagnosed. And of course you are absolutely correct that you can maintain excellent control with diet and lifestyle. It does need a little determination and willpower to start with, but then it just becomes part of your normal way of life. If you want more information on this have a look round the Food forum and the Low-Carb forum for ideas. And of course please ask if you have any questions.
Let us know how you get on.