Gretchen Rubin. The Happiness Project (Revised Edition): Or, Why I Spent a Year Trying to Sing in the Morning, Clean My Closets, Fight Right, Read Aristotle, and Generally Have More Fun. Harper, 2015. 324 p. $16.

Author
Influential self-help guru.

Benefit
How Gretchen Rubin became Gretchen Rubin. 

This book can save your life.