India, Feb. 8 -- It was just another morning, four years after my cancer treatment, when I drove to my local pharmacy to pick up my medicine. The pharmacy was only a mile from my house, a familiar route I had taken countless times. But on my way back home, I made a wrong turn.As I looked around, trying to figure out how to get back, panic and confusion set in. I had no idea where I was or which way to go.Four years ago, this wouldn't have been a problem.

I would have simply turned around and found my way home without a second thought. Now, however, situations that were once routine and effortless feel frightening and overwhelming.Math used to be one of my strongest subjects. I could solve simple problems instantly. But over the past few ...