I'm not a parent, but I definitely suffer from the wanting-to-do-it-all syndrome: be a great programmer, traveler, friend, daughter, dog walker, writer, photographer, singer... Oh, and of course read everything I want to. I can only imagine how that will compound if I have children.
I guess I handle it by soaking in as many moments as I can throughout the day, trying to tell myself that each minute spent alive is a minute well spent. Exercise definitely helps! I hope your new mindset carries you far. :)