The needle in a magnetic compass points to magnetic north. Imagine you had a compass that always pointed in the direction of the greatest possible joy. Instead of pointing in the same direction all the time, it would change directions from time to time, indicating in each moment what tasks to work on, what decisions to make, and every other instruction you would need to lead you to the greatest long-term joy. What would you be willing to pay for such a device?
Such a device does exist, but no one can sell it to you. You have to make it yourself. The device is called a life plan, and this book will tell you how to make it. The good news is that the device works; the bad news is that it takes a little bit to describe how to make and use it, and it will only work if you follow the instructions.