Imagine going to sleep one night as yourself-the emotional, anxious person you've been all your life-but on awakening, not being able to recognize your face and body in the mirror. No longer feeling empathy, joy or love. But feeling no anxieties at all.

Imagine being afraid you've gone insane, and living in terror that all who know you might find out. Imagine trying to describe your 'altered state' to a succession of doubting psychiatrists.

And now imagine that lasts for sixty years.