Happiness consists mostly, other things being equal, of having the ability when you go to bed at night, think back of what you’ve done during the day, feeling that you have accomplished something useful… But uh- a man has to live with himself. And nobody knows himself like he does, what goes through your mind in the course of a day. If you go to bed at night, and you feel more or less satisfied and contented that you’ve done the best you could, you’ve been fairly successful and things have turned out fairly well for you during the day, what’s wrong with that? Isn’t that happiness?
Daniel Poole, on happiness.