Apparently if one can write easily and naturally with either hand but in opposite directions you're a "mirror writer". And mirror writing is yet another anomaly that sometimes happens on its own in an otherwise normal person, and sometimes occurs as part of neurological disorders that cause autism or mental retardation.
I figure there are people who have been defeated by me at Boggle who would be quite surprised to know that I would have trouble mirroring even the simplest gesture of someone who's facing me. I would see that their head was tilted, but determining which way and then telling my own body to do the same thing... that would be a major struggle. People assume someone who can read forwards, backwards, and upside down that must have at least a normal ability to differentiate one direction from another, but that's not always true. I will say that I am much better at such skills than when I was a kid.
Some people get frustrated that people see them as "dumb" because of their spatial skills. My problem was never that anyone thought I was dumb. No, they'd see me as so smart that there just had to be a psychological reason for everything. (If someone's IQ tests low and they're in adaptive PE because of coordination and spatial problems, people assume they don't get a driver's license because they don't have the skills. But if someone's IQ tests high and they're in adaptive PE because of coordination and spatial skills, people will see their not getting a driver's license as one more piece of evidence that they're cowering in fear of the world.)
I could be dead wrong on leads I follow, so I avoid saying too much. I will say that there are people who have a corpus callosum (the part that connects the hemispheres of the brain) that bends at an abnormal angle through the brain's language center, but fails to reach as far as the motion center at the base of the brain. There was one study of children with this disorder that found that the wider the bending angle the more over the top the storytelling behavior -- the more bent those children were on capturing an audience and hooking them. And that is but one example of a weakness that comes with a mirroring gift.