I found this a must-read: http://www.brainpickings.org/index.php/2013/06/07/annie-dillard-the-writing-life-1/. An excerpt:
There is no shortage of good days. It is good lives that are hard to come by. A life of good days lived in the senses is not enough. The life of sensation is the life of greed; it requires more and more. The life of the spirit requires less and less; time is ample and its passage sweet. Who would call a day spent reading a good day? But a life spent reading — that is a good life. A day that closely resembles every other day of the past ten or twenty years does not suggest itself as a good one. But who would not call Pasteur’s life a good one, or Thomas Mann’s?