A favorite, inspiring quote by George Bernard Shaw via Matt Goldman of blueman.com:
This is the true joy in life, being used for a purpose recognized by yourself as a mighty one. Being a force of nature instead of a feverish, selfish little clod of ailments and grievances complaining that the world will not devote itself to making you happy. I am of the opinion that my life belongs to the whole community and as I live it is my privilege – my privilege to do for it whatever I can. I want to be thoroughly used up when I die, for the harder I work the more I love. I rejoice in life for its own sake. Life is no brief candle to me; it is a sort of splendid torch which I’ve got a hold of for the moment and I want to make it burn as brightly as possible before handing it on to future generations.
-George Bernard Shaw