In the 19th year of what I thought was my very strong marriage, my wife looked me in the eye one morning and said, "I love you but I'm not in love with you anymore." I thought it was a cliche. I thought it was a joke. I thought it was very sick humor. Over the next 18 months, I learned that my wife was sincere: she wanted out of our marriage. This despite three children, a beautiful home in Pennsylvania, a marriage that friends often cited as a "perfect" marriage. In I Thought We Were Happy, I explore what happened to my so-called ideal marriage, what went wrong, why I failed to heed the...