The Philosophy of Stoicism

Stoicism is a philosophy based on the idea that most things in life lie outside our direct sphere of control. It's not external events that directly cause negative emotion, but rather what we tell ourselves about them. The classic serenity prayer says God grant me the serenity to accept that which i cannot change and the courage to change what i can. So if all you worry about over your own thoughts and your own actions, then i think that is a pretty good way of living a stress free life.