All of my activity since I've owned the Watch still shows in my activity app on the phone. I don't think it can delete prior history out of your health app. It'll be like adding another source for that info (steps, calories, workouts). Aside from the settings, installing apps, Apple Pay.. I didn't notice anything else missing when I did it.Have tried repairing the watch to my iphone with no improvement. Setting up as a new Watch I have not yet attempted. Besides having to redo my watch settings, Apple Pay, reinstall watch apps, etc, what data do I lose if I set up the watch as new without restoring from the last backup? Obviously I'll lose my activity for the day up that point (steps, calories, workouts). Do I lose historical health data associated with the watch?