Two other books I am most of the way through right now are Fearless, by Max Luxado, and The Happiness Advantage by Shawn Anchor. I have conveyed some of my learnings from Shawn's book. From a learning perspective I am valuing the way these two books are addressing the same overall issue but from different angles.
Ultimately fear keeps us from doing and enjoying so much. We fear failure so we don't try things. That might be the most fundamental way of saying it. Fear paralyzes us. It keeps us from enjoying everyday. So the simplicity described in The Happiness Advantage of being positive can be augmented by some knowledge of what keeps us from being positive. It is hard to be positive about success, when you actually are more ruled by fear of failure.
Most of us have personal experience with those who have had to deal with dying. Cancer or some other terminal disease robbing our friends of a full life here on earth…or has it? I have learned more from those who have significant obstacles to deal with than those who don't. Isn't it true that often those in situations where death is imminent enjoy life, friends and family all the more. They embrace the good, they find the good, they look for the good, because it is a waste, literally, of the life they have left to do otherwise. To accept the inevitable frees them up to pursue passionately everything they deem important. The cliche holds true, perhaps we should start saying it daily, live today as if it were your last.
The Bible has a similar thought, "This is the day the Lord has made (given), I will rejoice and be glad in it". (Psalm 118:24)