A great reference for keeping yourself focused on the important things, whatever they may be in your life. That project you're working on? Prioritize it. Literally make it the first thing you do every day. Make sure you're getting enough sleep. Make sure you don't fill time with noisy/wasteful distraction, but instead fill it with restful peace or activity.

That's my 4 line summary. Well worth reading. Bought a copy after reading a friend's.