Average happiness falls for the average person very gradually, from early twenties until early fifties. But at age 70, the population breaks up into two groups: one group that keeps getting happier all the way to the end and the other half that starts getting unhappier all theway to the end. And i've studied who's in the lower group, and it's not ordinary people. It's successful people. The data really support this. If you have a big party in your life, you're going to know when it's over. If you don't do anything with your life,. you're not going to be able to get back on track. That's what this book is