Happened to me. I have been hypochondric for years. And then it just turned to - who cares. I have had a break from my fears for one and a half years. Now they only return when I am really stressed out, like at the moment. But usually I can place those fears to "ah okay you're stressed, maybe take some pressure out" and they're gone. Have been wondering if it was due to being hypo as well, because when depressed I get more anxious again. But maybe it is just part of a successful learning process.