I also started with platelets over one million at age 39. Now I'm 69. I'm also JAK2 positive. After 30 years, I often hear from new hematologists (I've gone through a lot!) that I likely know more about living with the disease than they do, since they don't encounter it very often, especially for someone like me who's had it for 30 years. So, if it's a good doc, generally he/she looks at what I've done to treat it, the success I've had, and tell me to carry on and check in every 6 months. If HU is working at that low of a dose for you, that's great. I'd say that as long as HU is working well for you, try to minimize your stress and not worry too much. No one seems to really have answers to the "why" questions, and you may drive yourself crazy in your determination to figure it out. So I just decided to live comfortably with gray areas in my life!