As we live our lives day by day, it becomes obvious that there are some things we control, and there are many other things we have no control over.
"The chief task in life is simply this: to identify and separate matters so that I can say clearly to myself which are externals not under my control, and which have to do with the choices I actually control. Where then do I look for good and evil? Not to uncontrollable externals, but within myself to the choices that are my own."
-- Epictetus, Discourses, 2.5.4-5
So the secret to achieving true happiness is to focus on what you control and then make the best of that despite all of the other things happening around you.
