Ah, January. Season of diets and fasts and cleanses, of "Drynuary" and "Veganuary." Why does being virtuous always seem to mean giving up pleasure? This hour, we explore the concept of renunciation and our complicated feelings about it. Giving something up — whether a glass of wine or a way of life — can be hard and painful. The experience can change people in ways they don't expect — for better and for worse.