I suppose if you've never bitten your nails, there isn't any way to explain the habit. It's not enjoyable, really, but there is a certain satisfaction - pride in a job well done.
Anderson CooperDid you know that according to legend, the guy who became Buddha decided to seek enlightenment the day he got a touch of gray? "Gray hairs," the would-be Buddha said, "are like angels sent by the god of death".
Anderson Cooper