Today I learned that hair does not stop growing. When it reaches its maximum length, it just falls out and a new hair grows in its place. With hair follicles, there is only the growing stage and the dormant stage. And the duration of these stages is different for each person, and different for different parts of the body. Every few years, every hair on your head is replaced, like every skin cell is replaced, like most every other atom in your body.
Today I learned