Other times, diminished symptoms aren't as easily explained. While filming a documentary about optimism for ABC—Michael J. Fox: Adventures of an Incurable Optimist—Michael traveled to Bhutan, a kingdom in the Himalayas that measures the gross national happiness of its citizens.
"I don't know whether it was the altitude or the thinning of the blood or whatever, but I had much less symptoms," he says. "It was just an amazing place, and it really was special."