is it true that the virus can lie dorment for 10, 15, 20 years without any symptoms and then suddenly appear and require continued treatment?

This is very true, but as far as requiring "continued" treatment I would think if you went that long with out any symptoms or signs that your body has done a great job of keeping the OB away. If you are in a relationship surpressive therapy may be something you and your partner would want to talk about though just as an added precaution.