Someone who suffers a stroke in their left cerebral hemisphere will lose control over the right side of their body. Every doctor relies upon this well-known fact in performing neurological exams, but when I asked my doctor last week why this should be, all I got was a shoulder shrug. So I asked Professor Catherine Carr, a neuroscientist at the University of Maryland, College Park the same question –“No good answer,” she replied. Wow! Such a fundamental property of how our brain and body are wired together and no one seems to know why?