I just couldn't get enthusiastic about this book as a whole.
For one thing, I was about one third of the way through the book when I realized it might be meant to be a ninety-day daily devotional. I'm still not sure, but there are ninety two-page 'chapters', so that must be the intent. In the introduction, the author states "this book is the record of that experiment in joy", and so I expected a kind of journaling of the process. Instead it seems to be a collection of observations, meditations, and encouragements.
There are many wise and poetic insights which make it worth the read, and I found myself making notes to record some which I wanted to return to. "...We avoid rest because we think of it as doing nothing...", page 11. Thoughtful. "Forgetting that the kingdom of God is fundamentally about peace and joy, we act as if it's really about work, doing our duty, making enough money, building the church, organizing prayer meetings, or keeping other Christians in line." This sounds like an accurate assessment, as it would explain some situations I can think of.
Because the possibility of living life in constant joy was at the least difficult for me to envision, and at most impossible to achieve, this book did not completely "click" with me. Because the author admits to struggling with anxieties all his life, I value this book as a testament of someone who has actually achieved that kind of life, and so I will keep this book in my possession to refer to the quotations I have collected, and quite possibly give it another try in future.