Look at Jewish history. Unrelieved lamenting would be intolerable. So, for every ten Jews beating their breasts, God designated one to be crazy and amuse the breast-beaters. By the time I was five I knew I was that one.
Every human being has hundreds of separate people living under his skin. The talent of a writer is his ability to give them their separate names, identities, personalities and have them relate to other characters living with him.