There are various reasons as to why a person is left-handed. They might have hurt their right hand
and had to learn use their left hand. After using it for quite some time, they became use to it and are not
likely to return being a right-handed. But the most popular theory is that they are inherited by DNA.
Why doesn't it hurt when we cut our finger nails?
It doesn't hurt because there are no sensory nerves in our finger nails. If we hit our fingernail with a
hammer, it hurts because the force is transmitted to the underlying finger with its rich supply of sensory
nerves. But the fingernail itself is actually not living tissue, and it has no blood supply to ensure that we
don't bleed when we cut our fingernails. In short, no nerve supply, no pain.
