Somewhere over the years — I think it was during the high school days — I remember hearing that you can supposedly tell a person's handedness by looking at his or her thumbnail.
Hmm...curious. Whether it be an old wives' tale or has some scientific merit, tell me if this theory is true for you.
Compare your two thumbnails. Is one more squared-off at the base, particularly where your cuticle meets your lower nail bed? If so, does it correspond to your dominant hand or is this all a bunch of poppycock?