My parents had a greeting card message on their checkbook cover that usually makes me smile:

"It is better to be rich and healthy than it is to be poor and sick."

But Peter S. Beagle's The Last Unicorn has a "speech" I like, and the main theme there is, "The happy ending cannot come in the middle of the story." I remind myself of that and ask myself "Are you happy?" and if the answer is "No" then I keep on keeping on/working until I am :-)